net: Avoid duplicate getheaders requests.
net: Avoid duplicate getheaders requests.

The current logic for syncing headers may lead to lots of duplicate
getheaders requests being sent:  If a new block arrives while the node
is in headers sync, it will send getheaders in response to the block
announcement.  When the headers arrive, the message will be of maximum
size and so a follow-up request will be sent---all of that in addition
to the existing headers syncing.  This will create a second "chain" of
getheaders requests.  If more blocks arrive, this may even lead to
arbitrarily many parallel chains of redundant requests.

This patch changes the behaviour to only request more headers after a
maximum-sized message when it contained at least one unknown header.
This avoids sustaining parallel chains of redundant requests.

Note that this patch avoids the issues raised in the discussion of
https://github.com/bitcoin/bitcoin/pull/6821:  There is no risk of the
node being permanently blocked.  At the latest when a new block arrives
this will trigger a new getheaders request and restart syncing.

peercoin/peercoin,djpnewton/bitcoin,Diapolo/bitcoin,lbrtcoin/albertcoin,nomnombtc/bitcoin,gravio-net/graviocoin,pataquets/namecoin-core,btc1/bitcoin,UFOCoins/ufo,nbenoit/bitcoin,1185/starwels,metacoin/florincoin,BitcoinHardfork/bitcoin,andreaskern/bitcoin,rawodb/bitcoin,alecalve/bitcoin,fujicoin/fujicoin,wbchen99/bitcoin-hnote0,litecoin-project/litecore-litecoin,UASF/bitcoin,dgarage/bc3,isle2983/bitcoin,afk11/bitcoin,chaincoin/chaincoin,sebrandon1/bitcoin,dgarage/bc2,ahmedbodi/temp_vert,MarcoFalke/bitcoin,untrustbank/litecoin,AkioNak/bitcoin,GroestlCoin/GroestlCoin,rebroad/bitcoin,wiggi/huntercore,Anfauglith/iop-hd,mm-s/bitcoin,brandonrobertz/namecoin-core,CryptArc/bitcoin,Michagogo/bitcoin,litecoin-project/litecoin,MazaCoin/maza,h4x3rotab/BTCGPU,shouhuas/bitcoin,HashUnlimited/Einsteinium-Unlimited,wbchen99/bitcoin-hnote0,rawodb/bitcoin,mincoin-project/mincoin,awemany/BitcoinUnlimited,argentumproject/argentum,namecoin/namecoin-core,cannabiscoindev/cannabiscoin420,Kogser/bitcoin,Sjors/bitcoin,rnicoll/bitcoin,stamhe/bitcoin,gjhiggins/vcoincore,cculianu/bitcoin-abc,ahmedbodi/vertcoin,gzuser01/zetacoin-bitcoin,Rav3nPL/PLNcoin,kevcooper/bitcoin,BigBlueCeiling/augmentacoin,cculianu/bitcoin-abc,MarcoFalke/bitcoin,btcdrak/bitcoin,bdelzell/creditcoin-org-creditcoin,oklink-dev/bitcoin,jimmysong/bitcoin,domob1812/huntercore,zetacoin/zetacoin,reorder/viacoin,myriadteam/myriadcoin,peercoin/peercoin,deeponion/deeponion,nbenoit/bitcoin,wbchen99/bitcoin-hnote0,kazcw/bitcoin,StarbuckBG/BTCGPU,vertcoin/vertcoin,jonasschnelli/bitcoin,stamhe/bitcoin,BitcoinHardfork/bitcoin,andreaskern/bitcoin,Xekyo/bitcoin,Kogser/bitcoin,GroestlCoin/bitcoin,Xekyo/bitcoin,nathaniel-mahieu/bitcoin,ElementsProject/elements,dcousens/bitcoin,Anfauglith/iop-hd,ftrader-bitcoinabc/bitcoin-abc,BitzenyCoreDevelopers/bitzeny,jiangyonghang/bitcoin,Rav3nPL/PLNcoin,funkshelper/woodcore,matlongsi/micropay,sipsorcery/bitcoin,Michagogo/bitcoin,nikkitan/bitcoin,zcoinofficial/zcoin,ctwiz/stardust,sdaftuar/bitcoin,ryanofsky/bitcoin,bitcoinplusorg/xbcwalletsource,gjhiggins/vcoincore,cdecker/bitcoin,joshrabinowitz/bitcoin,rebroad/bitcoin,lateminer/bitcoin,martindale/elements,Sjors/bitcoin,starwels/starwels,segsignal/bitcoin,bitcoinknots/bitcoin,tdudz/elements,sbaks0820/bitcoin,domob1812/namecore,CryptArc/bitcoin,GlobalBoost/GlobalBoost,mm-s/bitcoin,prusnak/bitcoin,appop/bitcoin,midnightmagic/bitcoin,brandonrobertz/namecoin-core,ppcoin/ppcoin,sipsorcery/bitcoin,guncoin/guncoin,gzuser01/zetacoin-bitcoin,paveljanik/bitcoin,trippysalmon/bitcoin,Kogser/bitcoin,dogecoin/dogecoin,zcoinofficial/zcoin,emc2foundation/einsteinium,GroestlCoin/bitcoin,ixcoinofficialpage/master,dogecoin/dogecoin,peercoin/peercoin,sbaks0820/bitcoin,ajtowns/bitcoin,kevcooper/bitcoin,NicolasDorier/bitcoin,trippysalmon/bitcoin,fsb4000/bitcoin,bitcoin/bitcoin,dgarage/bc2,lbrtcoin/albertcoin,plncoin/PLNcoin_Core,gjhiggins/vcoincore,ahmedbodi/temp_vert,174high/bitcoin,BitcoinHardfork/bitcoin,174high/bitcoin,anditto/bitcoin,Flowdalic/bitcoin,gazbert/bitcoin,kazcw/bitcoin,randy-waterhouse/bitcoin,ryanxcharles/bitcoin,digibyte/digibyte,BTCGPU/BTCGPU,wangxinxi/litecoin,paveljanik/bitcoin,sbaks0820/bitcoin,Chancoin-core/CHANCOIN,bdelzell/creditcoin-org-creditcoin,yenliangl/bitcoin,vertcoin/vertcoin,daliwangi/bitcoin,aspanta/bitcoin,qtumproject/qtum,UASF/bitcoin,Jcing95/iop-hd,guncoin/guncoin,ahmedbodi/terracoin,laudaa/bitcoin,Flowdalic/bitcoin,Christewart/bitcoin,ctwiz/stardust,ElementsProject/elements,jl2012/litecoin,fujicoin/fujicoin,21E14/bitcoin,jambolo/bitcoin,bitcoinplusorg/xbcwalletsource,nathaniel-mahieu/bitcoin,awemany/BitcoinUnlimited,globaltoken/globaltoken,ericshawlinux/bitcoin,funkshelper/woodcore,ftrader-bitcoinabc/bitcoin-abc,goldcoin/goldcoin,goldcoin/Goldcoin-GLD,afk11/bitcoin,GroestlCoin/GroestlCoin,destenson/bitcoin--bitcoin,kallewoof/elements,rnicoll/dogecoin,bitbrazilcoin-project/bitbrazilcoin,gazbert/bitcoin,Rav3nPL/PLNcoin,lbryio/lbrycrd,ajtowns/bitcoin,untrustbank/litecoin,brandonrobertz/namecoin-core,randy-waterhouse/bitcoin,paveljanik/bitcoin,ryanxcharles/bitcoin,lbrtcoin/albertcoin,btc1/bitcoin,globaltoken/globaltoken,globaltoken/globaltoken,bitcoin/bitcoin,Cocosoft/bitcoin,r8921039/bitcoin,ryanxcharles/bitcoin,gjhiggins/vcoincore,domob1812/namecore,btc1/bitcoin,segsignal/bitcoin,patricklodder/dogecoin,domob1812/namecore,jimmysong/bitcoin,Bitcoin-ABC/bitcoin-abc,rnicoll/dogecoin,fujicoin/fujicoin,Bitcoin-ABC/bitcoin-abc,lateminer/bitcoin,maaku/bitcoin,dscotese/bitcoin,wiggi/huntercore,earonesty/bitcoin,bitreserve/bitcoin,matlongsi/micropay,AkioNak/bitcoin,senadmd/coinmarketwatch,ftrader-bitcoinabc/bitcoin-abc,Gazer022/bitcoin,rnicoll/dogecoin,ajtowns/bitcoin,nomnombtc/bitcoin,MarcoFalke/bitcoin,qtumproject/qtum,mruddy/bitcoin,reorder/viacoin,namecoin/namecore,core-bitcoin/bitcoin,svost/bitcoin,ryanofsky/bitcoin,Anfauglith/iop-hd,Bitcoin-ABC/bitcoin-abc,martindale/elements,StarbuckBG/BTCGPU,afk11/bitcoin,AdrianaDinca/bitcoin,tjps/bitcoin,jamesob/bitcoin,earonesty/bitcoin,MeshCollider/bitcoin,itmanagerro/tresting,reorder/viacoin,ryanofsky/bitcoin,n1bor/bitcoin,ppcoin/ppcoin,romanornr/viacoin,achow101/bitcoin,x-kalux/bitcoin_WiG-B,gmaxwell/bitcoin,Xekyo/bitcoin,wiggi/huntercore,jambolo/bitcoin,mincoin-project/mincoin,h4x3rotab/BTCGPU,r8921039/bitcoin,myriadteam/myriadcoin,sdaftuar/bitcoin,paveljanik/bitcoin,r8921039/bitcoin,xieta/mincoin,Mirobit/bitcoin,sstone/bitcoin,anditto/bitcoin,shaolinfry/litecoin,sdaftuar/bitcoin,shelvenzhou/BTCGPU,nikkitan/bitcoin,UASF/bitcoin,shaolinfry/litecoin,Electronic-Gulden-Foundation/egulden,itmanagerro/tresting,cculianu/bitcoin-abc,haobtc/bitcoin,174high/bitcoin,domob1812/bitcoin,aspanta/bitcoin,wangxinxi/litecoin,gameunits/gameunits,ericshawlinux/bitcoin,GlobalBoost/GlobalBoost,ShadowMyst/creativechain-core,wiggi/huntercore,zcoinofficial/zcoin,DigitalPandacoin/pandacoin,bitcoinec/bitcoinec,Michagogo/bitcoin,Electronic-Gulden-Foundation/egulden,nlgcoin/guldencoin-official,domob1812/huntercore,kevcooper/bitcoin,anditto/bitcoin,bitcoinsSG/bitcoin,Flowdalic/bitcoin,awemany/BitcoinUnlimited,x-kalux/bitcoin_WiG-B,Electronic-Gulden-Foundation/egulden,goldcoin/Goldcoin-GLD,bdelzell/creditcoin-org-creditcoin,argentumproject/argentum,myriadcoin/myriadcoin,instagibbs/bitcoin,shouhuas/bitcoin,yenliangl/bitcoin,ixcoinofficialpage/master,patricklodder/dogecoin,argentumproject/argentum,fsb4000/bitcoin,simonmulser/bitcoin,bitcoinsSG/bitcoin,senadmd/coinmarketwatch,elecoin/elecoin,sdaftuar/bitcoin,achow101/bitcoin,ElementsProject/elements,magacoin/magacoin,zcoinofficial/zcoin,pinheadmz/bitcoin,untrustbank/litecoin,BitcoinPOW/BitcoinPOW,appop/bitcoin,romanornr/viacoin,mm-s/bitcoin,ftrader-bitcoinabc/bitcoin-abc,UFOCoins/ufo,zetacoin/zetacoin,nomnombtc/bitcoin,core-bitcoin/bitcoin,s-matthew-english/bitcoin,psionin/smartcoin,AdrianaDinca/bitcoin,lbrtcoin/albertcoin,oklink-dev/bitcoin,tjps/bitcoin,Mirobit/bitcoin,psionin/smartcoin,Rav3nPL/PLNcoin,bitreserve/bitcoin,CryptArc/bitcoin,emc2foundation/einsteinium,bitcoinsSG/bitcoin,cryptoprojects/ultimateonlinecash,gmaxwell/bitcoin,21E14/bitcoin,ryanofsky/bitcoin,bitcoinplusorg/xbcwalletsource,argentumproject/argentum,JeremyRubin/bitcoin,h4x3rotab/BTCGPU,21E14/bitcoin,lbryio/lbrycrd,zcoinofficial/zcoin,paveljanik/bitcoin,jlopp/statoshi,Bitcoin-ABC/bitcoin-abc,core-bitcoin/bitcoin,jiangyonghang/bitcoin,pataquets/namecoin-core,btcdrak/bitcoin,AkioNak/bitcoin,NicolasDorier/bitcoin,Michagogo/bitcoin,practicalswift/bitcoin,bitcoinknots/bitcoin,monacoinproject/monacoin,segwit/atbcoin-insight,magacoin/magacoin,goldcoin/goldcoin,UFOCoins/ufo,segwit/atbcoin-insight,EthanHeilman/bitcoin,droark/bitcoin,dpayne9000/Rubixz-Coin,pstratem/bitcoin,dogecoin/dogecoin,daliwangi/bitcoin,goldcoin/Goldcoin-GLD,kallewoof/elements,mruddy/bitcoin,deeponion/deeponion,wellenreiter01/Feathercoin,digibyte/digibyte,awemany/BitcoinUnlimited,tdudz/elements,bitbrazilcoin-project/bitbrazilcoin,domob1812/bitcoin,BTCGPU/BTCGPU,bespike/litecoin,r8921039/bitcoin,btcdrak/bitcoin,1185/starwels,TheBlueMatt/bitcoin,emc2foundation/einsteinium,dgarage/bc2,starwels/starwels,Kogser/bitcoin,midnightmagic/bitcoin,tjps/bitcoin,mruddy/bitcoin,jambolo/bitcoin,apoelstra/bitcoin,laudaa/bitcoin,MeshCollider/bitcoin,andreaskern/bitcoin,wangxinxi/litecoin,xieta/mincoin,mincoin-project/mincoin,Kogser/bitcoin,MeshCollider/bitcoin,shelvenzhou/BTCGPU,deeponion/deeponion,HashUnlimited/Einsteinium-Unlimited,FeatherCoin/Feathercoin,RHavar/bitcoin,jimmysong/bitcoin,Gazer022/bitcoin,rnicoll/bitcoin,myriadteam/myriadcoin,paveljanik/bitcoin,cannabiscoindev/cannabiscoin420,JeremyRubin/bitcoin,sebrandon1/bitcoin,goldcoin/Goldcoin-GLD,chaincoin/chaincoin,ericshawlinux/bitcoin,prusnak/bitcoin,bitcoinknots/bitcoin,Xekyo/bitcoin,xieta/mincoin,Rav3nPL/bitcoin,sdaftuar/bitcoin,core-bitcoin/bitcoin,laudaa/bitcoin,cannabiscoindev/cannabiscoin420,FeatherCoin/Feathercoin,fujicoin/fujicoin,prusnak/bitcoin,NicolasDorier/bitcoin,tecnovert/particl-core,pstratem/bitcoin,jl2012/litecoin,martindale/elements,Rav3nPL/PLNcoin,uphold/bitcoin,bitcoinsSG/bitcoin,myriadcoin/myriadcoin,untrustbank/litecoin,Alonzo-Coeus/bitcoin,bitcoinec/bitcoinec,bitcoin/bitcoin,JeremyRubin/bitcoin,ahmedbodi/terracoin,EthanHeilman/bitcoin,appop/bitcoin,magacoin/magacoin,haobtc/bitcoin,ryanofsky/bitcoin,brandonrobertz/namecoin-core,yenliangl/bitcoin,ahmedbodi/temp_vert,Friedbaumer/litecoin,Cocosoft/bitcoin,nbenoit/bitcoin,FeatherCoin/Feathercoin,GlobalBoost/GlobalBoost,svost/bitcoin,dgarage/bc3,droark/bitcoin,sebrandon1/bitcoin,bitcoinplusorg/xbcwalletsource,sebrandon1/bitcoin,Gazer022/bitcoin,FeatherCoin/Feathercoin,Bitcoin-ABC/bitcoin-abc,jtimon/bitcoin,qtumproject/qtum,fanquake/bitcoin,Electronic-Gulden-Foundation/egulden,simonmulser/bitcoin,namecoin/namecoin-core,deeponion/deeponion,BTCDDev/bitcoin,achow101/bitcoin,mm-s/bitcoin,jlopp/statoshi,BigBlueCeiling/augmentacoin,daliwangi/bitcoin,argentumproject/argentum,trippysalmon/bitcoin,bitcoinec/bitcoinec,jonasschnelli/bitcoin,tjps/bitcoin,appop/bitcoin,DigitalPandacoin/pandacoin,daliwangi/bitcoin,daliwangi/bitcoin,fsb4000/bitcoin,AdrianaDinca/bitcoin,jiangyonghang/bitcoin,tecnovert/particl-core,myriadcoin/myriadcoin,elecoin/elecoin,myriadcoin/myriadcoin,btc1/bitcoin,romanornr/viacoin,viacoin/viacoin,pstratem/bitcoin,n1bor/bitcoin,multicoins/marycoin,litecoin-project/litecore-litecoin,dgarage/bc3,CryptArc/bitcoin,dcousens/bitcoin,Sjors/bitcoin,sebrandon1/bitcoin,sdaftuar/bitcoin,MeshCollider/bitcoin,tecnovert/particl-core,haobtc/bitcoin,EthanHeilman/bitcoin,ftrader-bitcoinabc/bitcoin-abc,DigiByte-Team/digibyte,maaku/bitcoin,pinheadmz/bitcoin,cryptoprojects/ultimateonlinecash,lbryio/lbrycrd,viacoin/viacoin,multicoins/marycoin,dgarage/bc2,joshrabinowitz/bitcoin,qtumproject/qtum,fanquake/bitcoin,wangxinxi/litecoin,magacoin/magacoin,ajtowns/bitcoin,cryptoprojects/ultimateonlinecash,apoelstra/bitcoin,GlobalBoost/GlobalBoost,okinc/bitcoin,nikkitan/bitcoin,laudaa/bitcoin,OmniLayer/omnicore,zcoinofficial/zcoin,Bushstar/UFO-Project,isle2983/bitcoin,midnightmagic/bitcoin,jmcorgan/bitcoin,Friedbaumer/litecoin,Mirobit/bitcoin,rawodb/bitcoin,domob1812/huntercore,rnicoll/bitcoin,okinc/bitcoin,vmp32k/litecoin,gravio-net/graviocoin,dscotese/bitcoin,simonmulser/bitcoin,NicolasDorier/bitcoin,lateminer/bitcoin,pataquets/namecoin-core,nomnombtc/bitcoin,dscotese/bitcoin,experiencecoin/experiencecoin,appop/bitcoin,lbrtcoin/albertcoin,XertroV/bitcoin-nulldata,multicoins/marycoin,aspanta/bitcoin,vertcoin/vertcoin,senadmd/coinmarketwatch,segwit/atbcoin-insight,shelvenzhou/BTCGPU,ahmedbodi/temp_vert,1185/starwels,destenson/bitcoin--bitcoin,apoelstra/bitcoin,fanquake/bitcoin,dgarage/bc3,monacoinproject/monacoin,afk11/bitcoin,DigitalPandacoin/pandacoin,earonesty/bitcoin,myriadteam/myriadcoin,jimmysong/bitcoin,spiritlinxl/BTCGPU,jimmysong/bitcoin,RHavar/bitcoin,segwit/atbcoin-insight,sstone/bitcoin,nomnombtc/bitcoin,romanornr/viacoin,Christewart/bitcoin,domob1812/namecore,magacoin/magacoin,maaku/bitcoin,magacoin/magacoin,bdelzell/creditcoin-org-creditcoin,particl/particl-core,earonesty/bitcoin,namecoin/namecore,instagibbs/bitcoin,rebroad/bitcoin,lbryio/lbrycrd,yenliangl/bitcoin,goldcoin/goldcoin,sipsorcery/bitcoin,sstone/bitcoin,gavinandresen/bitcoin-git,okinc/bitcoin,mitchellcash/bitcoin,instagibbs/bitcoin,Theshadow4all/ShadowCoin,EntropyFactory/creativechain-core,Alonzo-Coeus/bitcoin,Michagogo/bitcoin,okinc/bitcoin,Jcing95/iop-hd,FeatherCoin/Feathercoin,mincoin-project/mincoin,itmanagerro/tresting,Kogser/bitcoin,StarbuckBG/BTCGPU,elecoin/elecoin,jambolo/bitcoin,NicolasDorier/bitcoin,destenson/bitcoin--bitcoin,starwels/starwels,domob1812/huntercore,Exgibichi/statusquo,trippysalmon/bitcoin,apoelstra/bitcoin,nathaniel-mahieu/bitcoin,chaincoin/chaincoin,laudaa/bitcoin,midnightmagic/bitcoin,itmanagerro/tresting,kazcw/bitcoin,ftrader-bitcoinabc/bitcoin-abc,alecalve/bitcoin,wbchen99/bitcoin-hnote0,bdelzell/creditcoin-org-creditcoin,plncoin/PLNcoin_Core,funkshelper/woodcore,wellenreiter01/Feathercoin,r8921039/bitcoin,Rav3nPL/PLNcoin,globaltoken/globaltoken,earonesty/bitcoin,dcousens/bitcoin,jiangyonghang/bitcoin,achow101/bitcoin,x-kalux/bitcoin_WiG-B,EthanHeilman/bitcoin,sarielsaz/sarielsaz,starwels/starwels,plncoin/PLNcoin_Core,Anfauglith/iop-hd,segsignal/bitcoin,thrasher-/litecoin,s-matthew-english/bitcoin,particl/particl-core,BitzenyCoreDevelopers/bitzeny,BTCDDev/bitcoin,gazbert/bitcoin,ShadowMyst/creativechain-core,elecoin/elecoin,OmniLayer/omnicore,guncoin/guncoin,maaku/bitcoin,mitchellcash/bitcoin,s-matthew-english/bitcoin,jamesob/bitcoin,wiggi/huntercore,zcoinofficial/zcoin,gameunits/gameunits,UFOCoins/ufo,domob1812/namecore,okinc/bitcoin,zetacoin/zetacoin,ftrader-bitcoinabc/bitcoin-abc,joshrabinowitz/bitcoin,tjps/bitcoin,patricklodder/dogecoin,sarielsaz/sarielsaz,litecoin-project/litecore-litecoin,BTCDDev/bitcoin,BitcoinPOW/BitcoinPOW,Friedbaumer/litecoin,UASF/bitcoin,fsb4000/bitcoin,tdudz/elements,Chancoin-core/CHANCOIN,gameunits/gameunits,ahmedbodi/terracoin,donaloconnor/bitcoin,aspanta/bitcoin,EntropyFactory/creativechain-core,patricklodder/dogecoin,Theshadow4all/ShadowCoin,digibyte/digibyte,nlgcoin/guldencoin-official,wellenreiter01/Feathercoin,Chancoin-core/CHANCOIN,sbaks0820/bitcoin,namecoin/namecoin-core,afk11/bitcoin,dpayne9000/Rubixz-Coin,mb300sd/bitcoin,rnicoll/dogecoin,segsignal/bitcoin,isle2983/bitcoin,Theshadow4all/ShadowCoin,mitchellcash/bitcoin,prusnak/bitcoin,kallewoof/bitcoin,Sjors/bitcoin,Alonzo-Coeus/bitcoin,okinc/bitcoin,Xekyo/bitcoin,jtimon/bitcoin,midnightmagic/bitcoin,n1bor/bitcoin,apoelstra/bitcoin,gjhiggins/vcoincore,mruddy/bitcoin,nathaniel-mahieu/bitcoin,particl/particl-core,gazbert/bitcoin,domob1812/namecore,BigBlueCeiling/augmentacoin,21E14/bitcoin,kevcooper/bitcoin,viacoin/viacoin,shouhuas/bitcoin,pstratem/bitcoin,jnewbery/bitcoin,bitbrazilcoin-project/bitbrazilcoin,GroestlCoin/bitcoin,djpnewton/bitcoin,Diapolo/bitcoin,ericshawlinux/bitcoin,CryptArc/bitcoin,r8921039/bitcoin,practicalswift/bitcoin,litecoin-project/litecoin,reorder/viacoin,DigiByte-Team/digibyte,cryptoprojects/ultimateonlinecash,nlgcoin/guldencoin-official,tecnovert/particl-core,jl2012/litecoin,rebroad/bitcoin,rebroad/bitcoin,randy-waterhouse/bitcoin,Electronic-Gulden-Foundation/egulden,MazaCoin/maza,mitchellcash/bitcoin,mb300sd/bitcoin,s-matthew-english/bitcoin,myriadteam/myriadcoin,DigitalPandacoin/pandacoin,Rav3nPL/bitcoin,gmaxwell/bitcoin,segwit/atbcoin-insight,globaltoken/globaltoken,digibyte/digibyte,lateminer/bitcoin,thrasher-/litecoin,svost/bitcoin,jtimon/bitcoin,DigiByte-Team/digibyte,Cocosoft/bitcoin,cculianu/bitcoin-abc,litecoin-project/litecoin,bitcoinknots/bitcoin,nlgcoin/guldencoin-official,kallewoof/elements,ppcoin/ppcoin,NicolasDorier/bitcoin,mm-s/bitcoin,Mirobit/bitcoin,bitcoinsSG/bitcoin,mitchellcash/bitcoin,Sjors/bitcoin,nathaniel-mahieu/bitcoin,plncoin/PLNcoin_Core,instagibbs/bitcoin,midnightmagic/bitcoin,StarbuckBG/BTCGPU,dogecoin/dogecoin,TheBlueMatt/bitcoin,HashUnlimited/Einsteinium-Unlimited,lbrtcoin/albertcoin,lbrtcoin/albertcoin,donaloconnor/bitcoin,Kogser/bitcoin,oklink-dev/bitcoin,kazcw/bitcoin,dgarage/bc2,gravio-net/graviocoin,jimmysong/bitcoin,randy-waterhouse/bitcoin,gazbert/bitcoin,multicoins/marycoin,wellenreiter01/Feathercoin,jlopp/statoshi,gavinandresen/bitcoin-git,particl/particl-core,cdecker/bitcoin,domob1812/bitcoin,argentumproject/argentum,vmp32k/litecoin,dscotese/bitcoin,cryptoprojects/ultimateonlinecash,nikkitan/bitcoin,laudaa/bitcoin,shelvenzhou/BTCGPU,jl2012/litecoin,XertroV/bitcoin-nulldata,monacoinproject/monacoin,GroestlCoin/GroestlCoin,untrustbank/litecoin,gavinandresen/bitcoin-git,pataquets/namecoin-core,RHavar/bitcoin,bespike/litecoin,rawodb/bitcoin,jl2012/litecoin,dpayne9000/Rubixz-Coin,dpayne9000/Rubixz-Coin,anditto/bitcoin,DigiByte-Team/digibyte,thrasher-/litecoin,mruddy/bitcoin,TheBlueMatt/bitcoin,dscotese/bitcoin,elecoin/elecoin,alecalve/bitcoin,cannabiscoindev/cannabiscoin420,jambolo/bitcoin,JeremyRubin/bitcoin,sebrandon1/bitcoin,BTCGPU/BTCGPU,jtimon/bitcoin,yenliangl/bitcoin,kevcooper/bitcoin,gmaxwell/bitcoin,MarcoFalke/bitcoin,cculianu/bitcoin-abc,Friedbaumer/litecoin,gmaxwell/bitcoin,lateminer/bitcoin,reorder/viacoin,destenson/bitcoin--bitcoin,uphold/bitcoin,21E14/bitcoin,lbrtcoin/albertcoin,vmp32k/litecoin,RHavar/bitcoin,Bitcoin-ABC/bitcoin-abc,vertcoin/vertcoin,donaloconnor/bitcoin,GroestlCoin/GroestlCoin,kallewoof/elements,itmanagerro/tresting,Cocosoft/bitcoin,oklink-dev/bitcoin,dogecoin/dogecoin,droark/bitcoin,dcousens/bitcoin,MazaCoin/maza,guncoin/guncoin,djpnewton/bitcoin,HashUnlimited/Einsteinium-Unlimited,brandonrobertz/namecoin-core,bitcoinec/bitcoinec,jiangyonghang/bitcoin,untrustbank/litecoin,Kogser/bitcoin,psionin/smartcoin,chaincoin/chaincoin,matlongsi/micropay,dscotese/bitcoin,shaolinfry/litecoin,BitzenyCoreDevelopers/bitzeny,andreaskern/bitcoin,bespike/litecoin,haobtc/bitcoin,namecoin/namecore,Mirobit/bitcoin,starwels/starwels,jiangyonghang/bitcoin,MeshCollider/bitcoin,tecnovert/particl-core,vmp32k/litecoin,BTCGPU/BTCGPU,174high/bitcoin,TheBlueMatt/bitcoin,droark/bitcoin,jlopp/statoshi,ixcoinofficialpage/master,TheBlueMatt/bitcoin,jmcorgan/bitcoin,fanquake/bitcoin,Gazer022/bitcoin,fsb4000/bitcoin,dgarage/bc3,thrasher-/litecoin,Bitcoin-ABC/bitcoin-abc,pataquets/namecoin-core,lbrtcoin/albertcoin,wangxinxi/litecoin,namecoin/namecore,djpnewton/bitcoin,shouhuas/bitcoin,gzuser01/zetacoin-bitcoin,Exgibichi/statusquo,RHavar/bitcoin,jonasschnelli/bitcoin,Christewart/bitcoin,peercoin/peercoin,guncoin/guncoin,elecoin/elecoin,gameunits/gameunits,h4x3rotab/BTCGPU,apoelstra/bitcoin,destenson/bitcoin--bitcoin,experiencecoin/experiencecoin,stamhe/bitcoin,Rav3nPL/bitcoin,anditto/bitcoin,zcoinofficial/zcoin,gazbert/bitcoin,pstratem/bitcoin,vertcoin/vertcoin,litecoin-project/litecoin,btcdrak/bitcoin,21E14/bitcoin,spiritlinxl/BTCGPU,peercoin/peercoin,earonesty/bitcoin,sbaks0820/bitcoin,jtimon/bitcoin,Anfauglith/iop-hd,ryanxcharles/bitcoin,qtumproject/qtum,stamhe/bitcoin,bitreserve/bitcoin,experiencecoin/experiencecoin,oklink-dev/bitcoin,dgarage/bc3,sstone/bitcoin,kallewoof/bitcoin,deeponion/deeponion,destenson/bitcoin--bitcoin,ahmedbodi/vertcoin,jnewbery/bitcoin,Theshadow4all/ShadowCoin,DigiByte-Team/digibyte,bitcoinplusorg/xbcwalletsource,oklink-dev/bitcoin,droark/bitcoin,gavinandresen/bitcoin-git,nbenoit/bitcoin,Flowdalic/bitcoin,BitcoinPOW/BitcoinPOW,vertcoin/vertcoin,mincoin-project/mincoin,multicoins/marycoin,GroestlCoin/bitcoin,btcdrak/bitcoin,vmp32k/litecoin,jamesob/bitcoin,wiggi/huntercore,fsb4000/bitcoin,Bitcoin-ABC/bitcoin-abc,HashUnlimited/Einsteinium-Unlimited,Exgibichi/statusquo,StarbuckBG/BTCGPU,UASF/bitcoin,bitbrazilcoin-project/bitbrazilcoin,BTCDDev/bitcoin,OmniLayer/omnicore,Gazer022/bitcoin,martindale/elements,plncoin/PLNcoin_Core,Friedbaumer/litecoin,tecnovert/particl-core,funkshelper/woodcore,dpayne9000/Rubixz-Coin,bitcoin/bitcoin,ajtowns/bitcoin,shaolinfry/litecoin,jlopp/statoshi,psionin/smartcoin,pinheadmz/bitcoin,pinheadmz/bitcoin,litecoin-project/litecore-litecoin,joshrabinowitz/bitcoin,tdudz/elements,MazaCoin/maza,nbenoit/bitcoin,bitcoinplusorg/xbcwalletsource,lateminer/bitcoin,Flowdalic/bitcoin,domob1812/bitcoin,Theshadow4all/ShadowCoin,peercoin/peercoin,jlopp/statoshi,uphold/bitcoin,vmp32k/litecoin,BTCGPU/BTCGPU,experiencecoin/experiencecoin,matlongsi/micropay,andreaskern/bitcoin,Diapolo/bitcoin,uphold/bitcoin,anditto/bitcoin,ElementsProject/elements,shouhuas/bitcoin,Electronic-Gulden-Foundation/egulden,romanornr/viacoin,zetacoin/zetacoin,jnewbery/bitcoin,spiritlinxl/BTCGPU,Rav3nPL/bitcoin,yenliangl/bitcoin,core-bitcoin/bitcoin,rnicoll/dogecoin,zcoinofficial/zcoin,instagibbs/bitcoin,fujicoin/fujicoin,bitcoin/bitcoin,JeremyRubin/bitcoin,MarcoFalke/bitcoin,ctwiz/stardust,EntropyFactory/creativechain-core,OmniLayer/omnicore,awemany/BitcoinUnlimited,kazcw/bitcoin,monacoinproject/monacoin,experiencecoin/experiencecoin,ctwiz/stardust,zetacoin/zetacoin,metacoin/florincoin,cculianu/bitcoin-abc,kallewoof/elements,h4x3rotab/BTCGPU,multicoins/marycoin,jonasschnelli/bitcoin,cannabiscoindev/cannabiscoin420,achow101/bitcoin,spiritlinxl/BTCGPU,patricklodder/dogecoin,prusnak/bitcoin,lbrtcoin/albertcoin,xieta/mincoin,Christewart/bitcoin,GlobalBoost/GlobalBoost,ShadowMyst/creativechain-core,AkioNak/bitcoin,ryanofsky/bitcoin,tdudz/elements,bitcoinec/bitcoinec,starwels/starwels,funkshelper/woodcore,brandonrobertz/namecoin-core,nikkitan/bitcoin,Bitcoin-ABC/bitcoin-abc,n1bor/bitcoin,simonmulser/bitcoin,trippysalmon/bitcoin,btc1/bitcoin,xieta/mincoin,bitcoinsSG/bitcoin,BitzenyCoreDevelopers/bitzeny,Anfauglith/iop-hd,Jcing95/iop-hd,Rav3nPL/bitcoin,thrasher-/litecoin,emc2foundation/einsteinium,AdrianaDinca/bitcoin,ftrader-bitcoinabc/bitcoin-abc,maaku/bitcoin,ixcoinofficialpage/master,ixcoinofficialpage/master,Xekyo/bitcoin,sarielsaz/sarielsaz,shelvenzhou/BTCGPU,ahmedbodi/vertcoin,kazcw/bitcoin,svost/bitcoin,deeponion/deeponion,zcoinofficial/zcoin,mb300sd/bitcoin,x-kalux/bitcoin_WiG-B,reorder/viacoin,gameunits/gameunits,BitzenyCoreDevelopers/bitzeny,Diapolo/bitcoin,bitbrazilcoin-project/bitbrazilcoin,sipsorcery/bitcoin,kallewoof/bitcoin,practicalswift/bitcoin,nathaniel-mahieu/bitcoin,wangxinxi/litecoin,AdrianaDinca/bitcoin,martindale/elements,bitbrazilcoin-project/bitbrazilcoin,andreaskern/bitcoin,OmniLayer/omnicore,ElementsProject/elements,rnicoll/bitcoin,s-matthew-english/bitcoin,trippysalmon/bitcoin,bdelzell/creditcoin-org-creditcoin,Bitcoin-ABC/bitcoin-abc,pinheadmz/bitcoin,fanquake/bitcoin,chaincoin/chaincoin,Friedbaumer/litecoin,FeatherCoin/Feathercoin,Diapolo/bitcoin,metacoin/florincoin,litecoin-project/litecoin,domob1812/huntercore,ahmedbodi/vertcoin,mb300sd/bitcoin,sstone/bitcoin,awemany/BitcoinUnlimited,qtumproject/qtum,segsignal/bitcoin,achow101/bitcoin,litecoin-project/litecoin,fanquake/bitcoin,shaolinfry/litecoin,BitzenyCoreDevelopers/bitzeny,AkioNak/bitcoin,particl/particl-core,GroestlCoin/bitcoin,zetacoin/zetacoin,BitcoinPOW/BitcoinPOW,n1bor/bitcoin,myriadteam/myriadcoin,aspanta/bitcoin,litecoin-project/litecore-litecoin,Flowdalic/bitcoin,nomnombtc/bitcoin,ixcoinofficialpage/master,Kogser/bitcoin,myriadcoin/myriadcoin,segwit/atbcoin-insight,DigitalPandacoin/pandacoin,GlobalBoost/GlobalBoost,ShadowMyst/creativechain-core,bitcoin/bitcoin,litecoin-project/litecore-litecoin,MazaCoin/maza,gavinandresen/bitcoin-git,tjps/bitcoin,jnewbery/bitcoin,namecoin/namecore,particl/particl-core,MeshCollider/bitcoin,EntropyFactory/creativechain-core,jambolo/bitcoin,goldcoin/goldcoin,nbenoit/bitcoin,randy-waterhouse/bitcoin,jmcorgan/bitcoin,jonasschnelli/bitcoin,cryptoprojects/ultimateonlinecash,martindale/elements,174high/bitcoin,kallewoof/bitcoin,ShadowMyst/creativechain-core,GlobalBoost/GlobalBoost,wbchen99/bitcoin-hnote0,ElementsProject/elements,monacoinproject/monacoin,viacoin/viacoin,dcousens/bitcoin,dogecoin/dogecoin,BigBlueCeiling/augmentacoin,shaolinfry/litecoin,Jcing95/iop-hd,ctwiz/stardust,alecalve/bitcoin,1185/starwels,digibyte/digibyte,sarielsaz/sarielsaz,gjhiggins/vcoincore,nlgcoin/guldencoin-official,viacoin/viacoin,globaltoken/globaltoken,UFOCoins/ufo,Bitcoin-ABC/bitcoin-abc,bespike/litecoin,Alonzo-Coeus/bitcoin,ftrader-bitcoinabc/bitcoin-abc,uphold/bitcoin,ahmedbodi/terracoin,ericshawlinux/bitcoin,n1bor/bitcoin,namecoin/namecoin-core,afk11/bitcoin,core-bitcoin/bitcoin,bitreserve/bitcoin,AdrianaDinca/bitcoin,Bushstar/UFO-Project,XertroV/bitcoin-nulldata,aspanta/bitcoin,Exgibichi/statusquo,pataquets/namecoin-core,svost/bitcoin,goldcoin/goldcoin,droark/bitcoin,1185/starwels,jmcorgan/bitcoin,Bitcoin-ABC/bitcoin-abc,bitcoinknots/bitcoin,gravio-net/graviocoin,Bushstar/UFO-Project,sarielsaz/sarielsaz,uphold/bitcoin,stamhe/bitcoin,donaloconnor/bitcoin,Theshadow4all/ShadowCoin,nikkitan/bitcoin,BigBlueCeiling/augmentacoin,Rav3nPL/bitcoin,matlongsi/micropay,XertroV/bitcoin-nulldata,maaku/bitcoin,mruddy/bitcoin,plncoin/PLNcoin_Core,AkioNak/bitcoin,mb300sd/bitcoin,alecalve/bitcoin,lbrtcoin/albertcoin,wellenreiter01/Feathercoin,BitcoinHardfork/bitcoin,Kogser/bitcoin,gzuser01/zetacoin-bitcoin,Christewart/bitcoin,namecoin/namecoin-core,segsignal/bitcoin,Mirobit/bitcoin,174high/bitcoin,djpnewton/bitcoin,spiritlinxl/BTCGPU,practicalswift/bitcoin,jtimon/bitcoin,bitcoinec/bitcoinec,goldcoin/Goldcoin-GLD,joshrabinowitz/bitcoin,itmanagerro/tresting,gavinandresen/bitcoin-git,jnewbery/bitcoin,rnicoll/bitcoin,goldcoin/Goldcoin-GLD,EntropyFactory/creativechain-core,psionin/smartcoin,metacoin/florincoin,BitcoinHardfork/bitcoin,namecoin/namecoin-core,bitreserve/bitcoin,UASF/bitcoin,Michagogo/bitcoin,jamesob/bitcoin,cdecker/bitcoin,x-kalux/bitcoin_WiG-B,OmniLayer/omnicore,Kogser/bitcoin,btc1/bitcoin,EthanHeilman/bitcoin,Jcing95/iop-hd,ftrader-bitcoinabc/bitcoin-abc,ahmedbodi/vertcoin,joshrabinowitz/bitcoin,sbaks0820/bitcoin,wbchen99/bitcoin-hnote0,Cocosoft/bitcoin,Kogser/bitcoin,Chancoin-core/CHANCOIN,Gazer022/bitcoin,jmcorgan/bitcoin,s-matthew-english/bitcoin,ericshawlinux/bitcoin,BitcoinHardfork/bitcoin,Christewart/bitcoin,MazaCoin/maza,Exgibichi/statusquo,appop/bitcoin,GroestlCoin/GroestlCoin,jl2012/litecoin,ShadowMyst/creativechain-core,donaloconnor/bitcoin,mm-s/bitcoin,practicalswift/bitcoin,romanornr/viacoin,ctwiz/stardust,metacoin/florincoin,sipsorcery/bitcoin,pstratem/bitcoin,pinheadmz/bitcoin,gameunits/gameunits,bespike/litecoin,rawodb/bitcoin,donaloconnor/bitcoin,digibyte/digibyte,h4x3rotab/BTCGPU,dgarage/bc2,RHavar/bitcoin,kallewoof/bitcoin,DigitalPandacoin/pandacoin,rawodb/bitcoin,jamesob/bitcoin,senadmd/coinmarketwatch,btcdrak/bitcoin,domob1812/bitcoin,Alonzo-Coeus/bitcoin,randy-waterhouse/bitcoin,domob1812/bitcoin,gmaxwell/bitcoin,bitreserve/bitcoin,monacoinproject/monacoin,ahmedbodi/temp_vert,goldcoin/goldcoin,metacoin/florincoin,isle2983/bitcoin,EthanHeilman/bitcoin,BTCDDev/bitcoin,x-kalux/bitcoin_WiG-B,isle2983/bitcoin,gzuser01/zetacoin-bitcoin,Jcing95/iop-hd,sipsorcery/bitcoin,ppcoin/ppcoin,GroestlCoin/GroestlCoin,spiritlinxl/BTCGPU,Diapolo/bitcoin,prusnak/bitcoin,ryanxcharles/bitcoin,cculianu/bitcoin-abc,Alonzo-Coeus/bitcoin,instagibbs/bitcoin,dcousens/bitcoin,JeremyRubin/bitcoin,Cocosoft/bitcoin,xieta/mincoin,sarielsaz/sarielsaz,shouhuas/bitcoin,stamhe/bitcoin,experiencecoin/experiencecoin,ryanxcharles/bitcoin,rebroad/bitcoin,nlgcoin/guldencoin-official,GroestlCoin/bitcoin,shelvenzhou/BTCGPU,DigiByte-Team/digibyte,haobtc/bitcoin,cculianu/bitcoin-abc,BitcoinPOW/BitcoinPOW,lbryio/lbrycrd,ajtowns/bitcoin,jamesob/bitcoin,svost/bitcoin,gravio-net/graviocoin,kallewoof/bitcoin,Bitcoin-ABC/bitcoin-abc,gzuser01/zetacoin-bitcoin,Bushstar/UFO-Project,EntropyFactory/creativechain-core,XertroV/bitcoin-nulldata,CryptArc/bitcoin,ahmedbodi/terracoin,mincoin-project/mincoin,emc2foundation/einsteinium,lbryio/lbrycrd,BitcoinPOW/BitcoinPOW,psionin/smartcoin,domob1812/huntercore,UFOCoins/ufo,Bushstar/UFO-Project,qtumproject/qtum,thrasher-/litecoin,cdecker/bitcoin,BigBlueCeiling/augmentacoin,wellenreiter01/Feathercoin,senadmd/coinmarketwatch,namecoin/namecore,haobtc/bitcoin,cdecker/bitcoin,StarbuckBG/BTCGPU,djpnewton/bitcoin,ahmedbodi/terracoin,BTCDDev/bitcoin,isle2983/bitcoin,matlongsi/micropay,XertroV/bitcoin-nulldata,cannabiscoindev/cannabiscoin420,daliwangi/bitcoin,simonmulser/bitcoin,guncoin/guncoin,argentumproject/argentum,viacoin/viacoin,cdecker/bitcoin,bespike/litecoin,myriadcoin/myriadcoin,lbryio/lbrycrd,HashUnlimited/Einsteinium-Unlimited,emc2foundation/einsteinium,1185/starwels,Bushstar/UFO-Project,lbrtcoin/albertcoin,practicalswift/bitcoin,Chancoin-core/CHANCOIN,fujicoin/fujicoin,MarcoFalke/bitcoin,sstone/bitcoin,alecalve/bitcoin,Exgibichi/statusquo,kevcooper/bitcoin,rnicoll/bitcoin,ahmedbodi/temp_vert,jmcorgan/bitcoin,simonmulser/bitcoin,dpayne9000/Rubixz-Coin,senadmd/coinmarketwatch,BTCGPU/BTCGPU,TheBlueMatt/bitcoin,ahmedbodi/vertcoin,Chancoin-core/CHANCOIN,mb300sd/bitcoin,mitchellcash/bitcoin,tdudz/elements,chaincoin/chaincoin,gravio-net/graviocoin,kallewoof/elements