fixing readme and configure script links to double-conv
fixing readme and configure script links to double-conv

Summary:
Fixing following the issues raised by nsuke on github
following his diff (https://github.com/facebook/folly/pull/112)

Test Plan: visual inspection, tested build on arch linux

Reviewed By: davejwatson@fb.com

Subscribers: folly-diffs@

FB internal diff: D1807378

Tasks: 5909189

Signature: t1:1807378:1422403093:ca024f396a27ecd9b304c57643f0107764a38ca1

alexst07/folly,lifei/folly,Eagle-X/folly,brunomorishita/folly,cole14/folly,gaoyingie/folly,CJstar/folly,juniway/folly,tomhughes/folly,gaoyingie/folly,chjp2046/folly,hongliangzhao/folly,tempbottle/folly,doctaweeks/folly,sonnyhu/folly,loversInJapan/folly,PPC64/folly,xzmagic/folly,loversInJapan/folly,theiver9827/folly,brunomorishita/folly,theiver9827/folly,raphaelamorim/folly,cppfool/folly,hongliangzhao/folly,fw1121/folly,theiver9827/folly,Orvid/folly,renyinew/folly,arg0/folly,brunomorishita/folly,tempbottle/folly,romange/folly,leolujuyi/folly,mqeizi/folly,facebook/folly,kernelim/folly,lifei/folly,wildinto/folly,mqeizi/folly,PoisonBOx/folly,bikong2/folly,rklabs/folly,upsoft/folly,renyinew/folly,sakishum/folly,zhiweicai/folly,xzmagic/folly,fw1121/folly,Orvid/folly,KSreeHarsha/folly,PoisonBOx/folly,bobegir/folly,colemancda/folly,sonnyhu/folly,sonnyhu/folly,mqeizi/folly,KSreeHarsha/folly,cole14/folly,fw1121/folly,Eagle-X/folly,colemancda/folly,facebook/folly,SammyK/folly,nickhen/folly,theiver9827/folly,project-zerus/folly,SeanRBurton/folly,facebook/folly,lifei/folly,constantine001/folly,colemancda/folly,rklabs/folly,nickhen/folly,SeanRBurton/folly,project-zerus/folly,tomhughes/folly,yangjin-unique/folly,floxard/folly,doctaweeks/folly,juniway/folly,gavioto/folly,colemancda/folly,stonegithubs/folly,guker/folly,gaoyingie/folly,sonnyhu/folly,raphaelamorim/folly,romange/folly,clearlinux/folly,floxard/folly,zhiweicai/folly,PoisonBOx/folly,nickhen/folly,romange/folly,bowlofstew/folly,arg0/folly,shaobz/folly,Hincoin/folly,chjp2046/folly,charsyam/folly,gavioto/folly,yangjin-unique/folly,SammyK/folly,bikong2/folly,guker/folly,clearlylin/folly,bowlofstew/folly,PPC64/folly,clearlinux/folly,romange/folly,ykarlsbrun/folly,gavioto/folly,leolujuyi/folly,KSreeHarsha/folly,clearlylin/folly,leolujuyi/folly,doctaweeks/folly,SeanRBurton/folly,PPC64/folly,bowlofstew/folly,Hincoin/folly,juniway/folly,cole14/folly,alexst07/folly,rklabs/folly,ykarlsbrun/folly,lifei/folly,project-zerus/folly,hongliangzhao/folly,tempbottle/folly,charsyam/folly,arg0/folly,doctaweeks/folly,Hincoin/folly,tomhughes/folly,clearlinux/folly,clearlinux/folly,Orvid/folly,tempbottle/folly,colemancda/folly,kernelim/folly,shaobz/folly,arg0/folly,chjp2046/folly,yangjin-unique/folly,leolujuyi/folly,sakishum/folly,shaobz/folly,xzmagic/folly,kernelim/folly,facebook/folly,SammyK/folly,reddit/folly,chjp2046/folly,yangjin-unique/folly,alexst07/folly,Eagle-X/folly,sonnyhu/folly,loversInJapan/folly,PPC64/folly,bikong2/folly,floxard/folly,bikong2/folly,kernelim/folly,cppfool/folly,loverszhaokai/folly,stonegithubs/folly,SeanRBurton/folly,cppfool/folly,ykarlsbrun/folly,constantine001/folly,gavioto/folly,project-zerus/folly,sakishum/folly,mqeizi/folly,reddit/folly,constantine001/folly,theiver9827/folly,juniway/folly,bobegir/folly,PoisonBOx/folly,PoisonBOx/folly,yangjin-unique/folly,raphaelamorim/folly,wildinto/folly,SeanRBurton/folly,constantine001/folly,Hincoin/folly,rklabs/folly,bsampath/folly,bsampath/folly,chjp2046/folly,charsyam/folly,reddit/folly,PPC64/folly,guker/folly,floxard/folly,arg0/folly,gavioto/folly,raphaelamorim/folly,shaobz/folly,xzmagic/folly,gaoyingie/folly,xzmagic/folly,stonegithubs/folly,alexst07/folly,clearlylin/folly,CJstar/folly,gaoyingie/folly,lifei/folly,sakishum/folly,Hincoin/folly,CJstar/folly,alexst07/folly,brunomorishita/folly,guker/folly,raphaelamorim/folly,wildinto/folly,loversInJapan/folly,Eagle-X/folly,bowlofstew/folly,upsoft/folly,bsampath/folly,loversInJapan/folly,bsampath/folly,ykarlsbrun/folly,Orvid/folly,tempbottle/folly,KSreeHarsha/folly,cppfool/folly,renyinew/folly,ykarlsbrun/folly,bsampath/folly,cole14/folly,renyinew/folly,zhiweicai/folly,guker/folly,clearlylin/folly,loverszhaokai/folly,tomhughes/folly,facebook/folly,rklabs/folly,clearlylin/folly,upsoft/folly,stonegithubs/folly,fw1121/folly,bobegir/folly,fw1121/folly,charsyam/folly,zhiweicai/folly,project-zerus/folly,sakishum/folly,wildinto/folly,renyinew/folly,upsoft/folly,CJstar/folly,SammyK/folly,SammyK/folly,bobegir/folly,upsoft/folly,loverszhaokai/folly,KSreeHarsha/folly,brunomorishita/folly,bikong2/folly,cppfool/folly,mqeizi/folly,clearlinux/folly,nickhen/folly,zhiweicai/folly,wildinto/folly,leolujuyi/folly,CJstar/folly,nickhen/folly,cole14/folly,reddit/folly,stonegithubs/folly,constantine001/folly,tomhughes/folly,shaobz/folly,romange/folly,juniway/folly,floxard/folly,loverszhaokai/folly,hongliangzhao/folly,hongliangzhao/folly,doctaweeks/folly,bowlofstew/folly,reddit/folly,kernelim/folly,Eagle-X/folly,bobegir/folly,loverszhaokai/folly,Orvid/folly