test: bring p2p_leak.py up to date.
test: bring p2p_leak.py up to date.

After the introduction of wtxidrelay and sendaddrv2 messages during
version handshake, extend p2p_leak.py test to reflect this.
Also, some minor fixes and doc improvements.

pataquets/namecoin-core,JeremyRubin/bitcoin,rnicoll/bitcoin,achow101/bitcoin,jlopp/statoshi,tecnovert/particl-core,rnicoll/bitcoin,ajtowns/bitcoin,tecnovert/particl-core,dscotese/bitcoin,kallewoof/bitcoin,jamesob/bitcoin,fanquake/bitcoin,MeshCollider/bitcoin,jlopp/statoshi,sipsorcery/bitcoin,Xekyo/bitcoin,MarcoFalke/bitcoin,instagibbs/bitcoin,lateminer/bitcoin,particl/particl-core,MarcoFalke/bitcoin,bitcoin/bitcoin,ElementsProject/elements,bitcoinsSG/bitcoin,domob1812/namecore,AkioNak/bitcoin,bitcoin/bitcoin,jambolo/bitcoin,anditto/bitcoin,n1bor/bitcoin,domob1812/namecore,domob1812/bitcoin,qtumproject/qtum,mruddy/bitcoin,bitcoinknots/bitcoin,prusnak/bitcoin,jambolo/bitcoin,yenliangl/bitcoin,ajtowns/bitcoin,rnicoll/bitcoin,MarcoFalke/bitcoin,jamesob/bitcoin,anditto/bitcoin,andreaskern/bitcoin,jambolo/bitcoin,sipsorcery/bitcoin,namecoin/namecore,instagibbs/bitcoin,namecoin/namecoin-core,mruddy/bitcoin,bitcoin/bitcoin,GroestlCoin/bitcoin,sstone/bitcoin,mruddy/bitcoin,domob1812/bitcoin,instagibbs/bitcoin,sipsorcery/bitcoin,jlopp/statoshi,namecoin/namecore,mruddy/bitcoin,JeremyRubin/bitcoin,jambolo/bitcoin,JeremyRubin/bitcoin,mm-s/bitcoin,fujicoin/fujicoin,AkioNak/bitcoin,yenliangl/bitcoin,namecoin/namecoin-core,qtumproject/qtum,MeshCollider/bitcoin,jambolo/bitcoin,ajtowns/bitcoin,ElementsProject/elements,particl/particl-core,lateminer/bitcoin,bitcoinknots/bitcoin,dscotese/bitcoin,apoelstra/bitcoin,bitcoin/bitcoin,dscotese/bitcoin,namecoin/namecore,kallewoof/bitcoin,AkioNak/bitcoin,GroestlCoin/GroestlCoin,lateminer/bitcoin,Sjors/bitcoin,fanquake/bitcoin,domob1812/bitcoin,apoelstra/bitcoin,particl/particl-core,namecoin/namecoin-core,GroestlCoin/bitcoin,jlopp/statoshi,pataquets/namecoin-core,anditto/bitcoin,anditto/bitcoin,mm-s/bitcoin,mm-s/bitcoin,ajtowns/bitcoin,namecoin/namecoin-core,dscotese/bitcoin,qtumproject/qtum,apoelstra/bitcoin,andreaskern/bitcoin,MeshCollider/bitcoin,jambolo/bitcoin,yenliangl/bitcoin,andreaskern/bitcoin,particl/particl-core,pataquets/namecoin-core,tecnovert/particl-core,kallewoof/bitcoin,ElementsProject/elements,instagibbs/bitcoin,pataquets/namecoin-core,achow101/bitcoin,fanquake/bitcoin,sipsorcery/bitcoin,rnicoll/bitcoin,lateminer/bitcoin,bitcoinknots/bitcoin,AkioNak/bitcoin,GroestlCoin/bitcoin,sipsorcery/bitcoin,jlopp/statoshi,mm-s/bitcoin,Xekyo/bitcoin,n1bor/bitcoin,fanquake/bitcoin,fujicoin/fujicoin,sipsorcery/bitcoin,tecnovert/particl-core,apoelstra/bitcoin,prusnak/bitcoin,sstone/bitcoin,GroestlCoin/GroestlCoin,Sjors/bitcoin,jamesob/bitcoin,Xekyo/bitcoin,mm-s/bitcoin,MeshCollider/bitcoin,MarcoFalke/bitcoin,GroestlCoin/bitcoin,andreaskern/bitcoin,kallewoof/bitcoin,domob1812/namecore,GroestlCoin/GroestlCoin,fanquake/bitcoin,bitcoinknots/bitcoin,n1bor/bitcoin,lateminer/bitcoin,domob1812/namecore,qtumproject/qtum,JeremyRubin/bitcoin,fanquake/bitcoin,fujicoin/fujicoin,Xekyo/bitcoin,Sjors/bitcoin,achow101/bitcoin,bitcoinsSG/bitcoin,particl/particl-core,JeremyRubin/bitcoin,bitcoinsSG/bitcoin,sstone/bitcoin,rnicoll/bitcoin,dscotese/bitcoin,namecoin/namecore,kallewoof/bitcoin,MeshCollider/bitcoin,domob1812/namecore,achow101/bitcoin,JeremyRubin/bitcoin,domob1812/namecore,Sjors/bitcoin,instagibbs/bitcoin,GroestlCoin/bitcoin,AkioNak/bitcoin,ElementsProject/elements,instagibbs/bitcoin,particl/particl-core,pataquets/namecoin-core,rnicoll/bitcoin,Xekyo/bitcoin,domob1812/bitcoin,namecoin/namecoin-core,mruddy/bitcoin,yenliangl/bitcoin,fujicoin/fujicoin,fujicoin/fujicoin,bitcoinknots/bitcoin,Xekyo/bitcoin,MarcoFalke/bitcoin,sstone/bitcoin,ElementsProject/elements,andreaskern/bitcoin,mruddy/bitcoin,namecoin/namecoin-core,anditto/bitcoin,yenliangl/bitcoin,ElementsProject/elements,MarcoFalke/bitcoin,ajtowns/bitcoin,GroestlCoin/GroestlCoin,n1bor/bitcoin,domob1812/bitcoin,AkioNak/bitcoin,bitcoinsSG/bitcoin,bitcoinsSG/bitcoin,namecoin/namecore,GroestlCoin/GroestlCoin,n1bor/bitcoin,kallewoof/bitcoin,andreaskern/bitcoin,fujicoin/fujicoin,apoelstra/bitcoin,qtumproject/qtum,jamesob/bitcoin,sstone/bitcoin,domob1812/bitcoin,lateminer/bitcoin,mm-s/bitcoin,jlopp/statoshi,MeshCollider/bitcoin,prusnak/bitcoin,jamesob/bitcoin,bitcoin/bitcoin,bitcoin/bitcoin,yenliangl/bitcoin,jamesob/bitcoin,apoelstra/bitcoin,Sjors/bitcoin,n1bor/bitcoin,dscotese/bitcoin,tecnovert/particl-core,namecoin/namecore,prusnak/bitcoin,achow101/bitcoin,GroestlCoin/GroestlCoin,prusnak/bitcoin,tecnovert/particl-core,sstone/bitcoin,ajtowns/bitcoin,anditto/bitcoin,bitcoinsSG/bitcoin,qtumproject/qtum,pataquets/namecoin-core,GroestlCoin/bitcoin,achow101/bitcoin,prusnak/bitcoin,qtumproject/qtum