Implement -[RACSignal bind:] from scratch, without -flatten:
Implement -[RACSignal bind:] from scratch, without -flatten:

The resulting combined logic should be easier to follow and fix.

dz1111/ReactiveCocoa,mxxiv/ReactiveCocoa,walkingsmarts/ReactiveCocoa,jackywpy/ReactiveCocoa,koamac/ReactiveCocoa,j364960953/ReactiveCocoa,lixar/ReactiveCocoa,PSPDFKit-labs/ReactiveCocoa,hoanganh6491/ReactiveCocoa,kiurentu/ReactiveCocoa,zzzworm/ReactiveCocoa,monkeydbobo/ReactiveCocoa,eyu1988/ReactiveCocoa,Pikdays/ReactiveCocoa,AlanJN/ReactiveCocoa,ShawnLeee/ReactiveCocoa,yoichitgy/ReactiveCocoa,ReactiveCocoa/ReactiveSwift,AndyZhaoHe/ReactiveCocoa,bscarano/ReactiveCocoa,towik/ReactiveCocoa,xiaoliyang/ReactiveCocoa,Pingco/ReactiveCocoa,tiger8888/ReactiveCocoa,zzqiltw/ReactiveCocoa,andersio/ReactiveCocoa,dullgrass/ReactiveCocoa,tiger8888/ReactiveCocoa,chao95957/ReactiveCocoa,taylormoonxu/ReactiveCocoa,bscarano/ReactiveCocoa,rpowelll/ReactiveCocoa,xiaobing2007/ReactiveCocoa,bensonday/ReactiveCocoa,stevielu/ReactiveCocoa,howandhao/ReactiveCocoa,jackywpy/ReactiveCocoa,fhchina/ReactiveCocoa,stupidfive/ReactiveCocoa,xiaoliyang/ReactiveCocoa,BlessNeo/ReactiveCocoa,SanChain/ReactiveCocoa,zhiwen1024/ReactiveCocoa,zhenlove/ReactiveCocoa,terry408911/ReactiveCocoa,add715/ReactiveCocoa,jaylib/ReactiveCocoa,AndyZhaoHe/ReactiveCocoa,jam891/ReactiveCocoa,ddc391565320/ReactiveCocoa,dachaoisme/ReactiveCocoa,Eveian/ReactiveCocoa,gengjf/ReactiveCocoa,buildo/ReactiveCocoa,juliangrosshauser/ReactiveCocoa,chao95957/ReactiveCocoa,jianwoo/ReactiveCocoa,Remitly/ReactiveCocoa,isghe/ReactiveCocoa,wangqi211/ReactiveCocoa,xiaobing2007/ReactiveCocoa,cstars135/ReactiveCocoa,buildo/ReactiveCocoa,yoichitgy/ReactiveCocoa,tzongw/ReactiveCocoa,fanghao085/ReactiveCocoa,AlanJN/ReactiveCocoa,wpstarnice/ReactiveCocoa,kaylio/ReactiveCocoa,fanghao085/ReactiveCocoa,almassapargali/ReactiveCocoa,zhiwen1024/ReactiveCocoa,tiger8888/ReactiveCocoa,imkerberos/ReactiveCocoa,natan/ReactiveCocoa,mtxs007/ReactiveCocoa,Ray0218/ReactiveCocoa,wangqi211/ReactiveCocoa,200895045/ReactiveCocoa,Adlai-Holler/ReactiveCocoa,gabemdev/ReactiveCocoa,bencochran/ReactiveCocoa,on99/ReactiveCocoa,dullgrass/ReactiveCocoa,brightcove/ReactiveCocoa,sujeking/ReactiveCocoa,mattpetters/ReactiveCocoa,natestedman/ReactiveCocoa,libiao88/ReactiveCocoa,shuxiashusheng/ReactiveCocoa,imkerberos/ReactiveCocoa,CCOOOOLL/ReactiveCocoa,tonyarnold/ReactiveCocoa,leichunfeng/ReactiveCocoa,ioshger0125/ReactiveCocoa,GuitarPlayer-Ma/ReactiveCocoa,chieryw/ReactiveCocoa,cnbin/ReactiveCocoa,sujeking/ReactiveCocoa,jianwoo/ReactiveCocoa,OnTheWay1988/ReactiveCocoa,bscarano/ReactiveCocoa,jackywpy/ReactiveCocoa,victorlin/ReactiveCocoa,Liquidsoul/ReactiveCocoa,zhaoguohui/ReactiveCocoa,jaylib/ReactiveCocoa,DongDongDongDong/ReactiveCocoa,sujeking/ReactiveCocoa,mtxs007/ReactiveCocoa,eliperkins/ReactiveCocoa,beni55/ReactiveCocoa,OneSmallTree/ReactiveCocoa,Khan/ReactiveCocoa,paulyoung/ReactiveCocoa,brightcove/ReactiveCocoa,sugar2010/ReactiveCocoa,zhenlove/ReactiveCocoa,yangshengchaoios/ReactiveCocoa,almassapargali/ReactiveCocoa,dachaoisme/ReactiveCocoa,jam891/ReactiveCocoa,natan/ReactiveCocoa,tipbit/ReactiveCocoa,yangyangluoluo/ReactiveCocoa,kiurentu/ReactiveCocoa,qq644531343/ReactiveCocoa,GuitarPlayer-Ma/ReactiveCocoa,RuiAAPeres/ReactiveCocoa,CCOOOOLL/ReactiveCocoa,cstars135/ReactiveCocoa,AlanJN/ReactiveCocoa,SmartEncounter/ReactiveCocoa,yaoxiaoyong/ReactiveCocoa,sdhzwm/ReactiveCocoa,ceekayel/ReactiveCocoa,longv2go/ReactiveCocoa,wpstarnice/ReactiveCocoa,zhigang1992/ReactiveCocoa,ericzhou2008/ReactiveCocoa,ailyanlu/ReactiveCocoa,FelixYin66/ReactiveCocoa,Pikdays/ReactiveCocoa,esttorhe/ReactiveCocoa,isghe/ReactiveCocoa,nikita-leonov/ReactiveCocoa,brasbug/ReactiveCocoa,yytong/ReactiveCocoa,xulibao/ReactiveCocoa,liufeigit/ReactiveCocoa,hj3938/ReactiveCocoa,victorlin/ReactiveCocoa,JohnJin007/ReactiveCocoa,ShawnLeee/ReactiveCocoa,Ethan89/ReactiveCocoa,fhchina/ReactiveCocoa,itschaitanya/ReactiveCocoa,windgo/ReactiveCocoa,sandyway/ReactiveCocoa,isghe/ReactiveCocoa,ailyanlu/ReactiveCocoa,stevielu/ReactiveCocoa,shaohung001/ReactiveCocoa,Rupert-RR/ReactiveCocoa,koamac/ReactiveCocoa,Ricowere/ReactiveCocoa,beni55/ReactiveCocoa,200895045/ReactiveCocoa,eliperkins/ReactiveCocoa,tonyli508/ReactiveCocoa,eyu1988/ReactiveCocoa,tornade0913/ReactiveCocoa,Rupert-RR/ReactiveCocoa,zhukaixy/ReactiveCocoa,BlessNeo/ReactiveCocoa,luerhouhou/ReactiveCocoa,buildo/ReactiveCocoa,JohnJin007/ReactiveCocoa,DongDongDongDong/ReactiveCocoa,loupman/ReactiveCocoa,stevielu/ReactiveCocoa,itschaitanya/ReactiveCocoa,ztchena/ReactiveCocoa,mxxiv/ReactiveCocoa,bencochran/ReactiveCocoa,Farteen/ReactiveCocoa,xumaolin/ReactiveCocoa,Farteen/ReactiveCocoa,vincentiss/ReactiveCocoa,zhukaixy/ReactiveCocoa,takeshineshiro/ReactiveCocoa,mtxs007/ReactiveCocoa,hilllinux/ReactiveCocoa,yytong/ReactiveCocoa,kaylio/ReactiveCocoa,smilypeda/ReactiveCocoa,335g/ReactiveCocoa,ztchena/ReactiveCocoa,paulyoung/ReactiveCocoa,Ricowere/ReactiveCocoa,brightcove/ReactiveCocoa,sdhzwm/ReactiveCocoa,calebd/ReactiveCocoa,yaoxiaoyong/ReactiveCocoa,cnbin/ReactiveCocoa,LHDsimon/ReactiveCocoa,WEIBP/ReactiveCocoa,cnbin/ReactiveCocoa,huiping192/ReactiveCocoa,on99/ReactiveCocoa,shuxiashusheng/ReactiveCocoa,icepy/ReactiveCocoa,on99/ReactiveCocoa,emodeqidao/ReactiveCocoa,pzw224/ReactiveCocoa,tzongw/ReactiveCocoa,zhukaixy/ReactiveCocoa,335g/ReactiveCocoa,hoanganh6491/ReactiveCocoa,smilypeda/ReactiveCocoa,tonyarnold/ReactiveCocoa,rpowelll/ReactiveCocoa,nickcheng/ReactiveCocoa,kevin-zqw/ReactiveCocoa,bencochran/ReactiveCocoa,lixar/ReactiveCocoa,AllanChen/ReactiveCocoa,swizzlr/ReactiveCocoa,bensonday/ReactiveCocoa,smilypeda/ReactiveCocoa,KJin99/ReactiveCocoa,gengjf/ReactiveCocoa,goodheart/ReactiveCocoa,zxq3220122/ReactiveCocoa,stupidfive/ReactiveCocoa,imkerberos/ReactiveCocoa,dskatz22/ReactiveCocoa,CQXfly/ReactiveCocoa,pzw224/ReactiveCocoa,terry408911/ReactiveCocoa,monkeydbobo/ReactiveCocoa,dz1111/ReactiveCocoa,OnTheWay1988/ReactiveCocoa,xumaolin/ReactiveCocoa,kevin-zqw/ReactiveCocoa,nikita-leonov/ReactiveCocoa,gabemdev/ReactiveCocoa,OneSmallTree/ReactiveCocoa,msdgwzhy6/ReactiveCocoa,JackLian/ReactiveCocoa,ericzhou2008/ReactiveCocoa,alvinvarghese/ReactiveCocoa,vincentiss/ReactiveCocoa,victorlin/ReactiveCocoa,yonekawa/ReactiveCocoa,valleyman86/ReactiveCocoa,PSPDFKit-labs/ReactiveCocoa,Pikdays/ReactiveCocoa,leelili/ReactiveCocoa,Carthage/ReactiveCocoa,llb1119/test,Adlai-Holler/ReactiveCocoa,andersio/ReactiveCocoa,zhaoguohui/ReactiveCocoa,KuPai32G/ReactiveCocoa,KuPai32G/ReactiveCocoa,Carthage/ReactiveCocoa,DongDongDongDong/ReactiveCocoa,BrooksWon/ReactiveCocoa,calebd/ReactiveCocoa,ReactiveCocoa/ReactiveSwift,jaylib/ReactiveCocoa,tipbit/ReactiveCocoa,richeterre/ReactiveCocoa,ericzhou2008/ReactiveCocoa,xulibao/ReactiveCocoa,walkingsmarts/ReactiveCocoa,Farteen/ReactiveCocoa,windgo/ReactiveCocoa,richeterre/ReactiveCocoa,hilllinux/ReactiveCocoa,Ethan89/ReactiveCocoa,jsslai/ReactiveCocoa,hilllinux/ReactiveCocoa,kaylio/ReactiveCocoa,chieryw/ReactiveCocoa,sugar2010/ReactiveCocoa,koamac/ReactiveCocoa,longv2go/ReactiveCocoa,SmartEncounter/ReactiveCocoa,liufeigit/ReactiveCocoa,brasbug/ReactiveCocoa,SuPair/ReactiveCocoa,qq644531343/ReactiveCocoa,Liquidsoul/ReactiveCocoa,dskatz22/ReactiveCocoa,nikita-leonov/ReactiveCocoa,ShawnLeee/ReactiveCocoa,zhigang1992/ReactiveCocoa,BrooksWon/ReactiveCocoa,tonyarnold/ReactiveCocoa,almassapargali/ReactiveCocoa,zhaoguohui/ReactiveCocoa,CQXfly/ReactiveCocoa,ailyanlu/ReactiveCocoa,yytong/ReactiveCocoa,liufeigit/ReactiveCocoa,Ethan89/ReactiveCocoa,sugar2010/ReactiveCocoa,LHDsimon/ReactiveCocoa,mattpetters/ReactiveCocoa,zxq3220122/ReactiveCocoa,luerhouhou/ReactiveCocoa,BlessNeo/ReactiveCocoa,icepy/ReactiveCocoa,KJin99/ReactiveCocoa,jeelun/ReactiveCocoa,Eveian/ReactiveCocoa,hoanganh6491/ReactiveCocoa,valleyman86/ReactiveCocoa,cogddo/ReactiveCocoa,shaohung001/ReactiveCocoa,Eveian/ReactiveCocoa,zzzworm/ReactiveCocoa,xiaoliyang/ReactiveCocoa,Juraldinio/ReactiveCocoa,jrmiddle/ReactiveCocoa,OnTheWay1988/ReactiveCocoa,longv2go/ReactiveCocoa,jeelun/ReactiveCocoa,goodheart/ReactiveCocoa,yangyangluoluo/ReactiveCocoa,ceekayel/ReactiveCocoa,huiping192/ReactiveCocoa,yaoxiaoyong/ReactiveCocoa,natestedman/ReactiveCocoa,leichunfeng/ReactiveCocoa,monkeydbobo/ReactiveCocoa,dullgrass/ReactiveCocoa,sdhzwm/ReactiveCocoa,hbucius/ReactiveCocoa,taylormoonxu/ReactiveCocoa,eyu1988/ReactiveCocoa,beni55/ReactiveCocoa,jrmiddle/ReactiveCocoa,alvinvarghese/ReactiveCocoa,zxq3220122/ReactiveCocoa,tornade0913/ReactiveCocoa,zhenlove/ReactiveCocoa,jam891/ReactiveCocoa,taylormoonxu/ReactiveCocoa,howandhao/ReactiveCocoa,Remitly/ReactiveCocoa,SuPair/ReactiveCocoa,windgo/ReactiveCocoa,RuiAAPeres/ReactiveCocoa,ohwutup/ReactiveCocoa,walkingsmarts/ReactiveCocoa,paulyoung/ReactiveCocoa,loupman/ReactiveCocoa,DreamHill/ReactiveCocoa,towik/ReactiveCocoa,chao95957/ReactiveCocoa,ddc391565320/ReactiveCocoa,yizzuide/ReactiveCocoa,dz1111/ReactiveCocoa,Ray0218/ReactiveCocoa,brasbug/ReactiveCocoa,jianwoo/ReactiveCocoa,OneSmallTree/ReactiveCocoa,rpowelll/ReactiveCocoa,DreamHill/ReactiveCocoa,Ricowere/ReactiveCocoa,natan/ReactiveCocoa,cogddo/ReactiveCocoa,fanghao085/ReactiveCocoa,clg0118/ReactiveCocoa,takeshineshiro/ReactiveCocoa,DreamHill/ReactiveCocoa,esttorhe/ReactiveCocoa,Rupert-RR/ReactiveCocoa,hj3938/ReactiveCocoa,terry408911/ReactiveCocoa,wpstarnice/ReactiveCocoa,esttorhe/ReactiveCocoa,Adlai-Holler/ReactiveCocoa,zzqiltw/ReactiveCocoa,Ray0218/ReactiveCocoa,hbucius/ReactiveCocoa,add715/ReactiveCocoa,tonyli508/ReactiveCocoa,chieryw/ReactiveCocoa,natestedman/ReactiveCocoa,calebd/ReactiveCocoa,nickcheng/ReactiveCocoa,dskatz22/ReactiveCocoa,j364960953/ReactiveCocoa,emodeqidao/ReactiveCocoa,huiping192/ReactiveCocoa,kiurentu/ReactiveCocoa,sandyway/ReactiveCocoa,ioshger0125/ReactiveCocoa,yonekawa/ReactiveCocoa,FelixYin66/ReactiveCocoa,bensonday/ReactiveCocoa,Juraldinio/ReactiveCocoa,200895045/ReactiveCocoa,SanChain/ReactiveCocoa,WEIBP/ReactiveCocoa,ReactiveCocoa/ReactiveSwift,jsslai/ReactiveCocoa,jaylib/ReactiveCocoa,ikesyo/ReactiveCocoa,yizzuide/ReactiveCocoa,BrooksWon/ReactiveCocoa,Ricowere/ReactiveCocoa,Pingco/ReactiveCocoa,takeshineshiro/ReactiveCocoa,wangqi211/ReactiveCocoa,AndyZhaoHe/ReactiveCocoa,add715/ReactiveCocoa,tonyli508/ReactiveCocoa,LHDsimon/ReactiveCocoa,WEIBP/ReactiveCocoa,JackLian/ReactiveCocoa,SuPair/ReactiveCocoa,msdgwzhy6/ReactiveCocoa,yangshengchaoios/ReactiveCocoa,vincentiss/ReactiveCocoa,zzzworm/ReactiveCocoa,yoichitgy/ReactiveCocoa,SanChain/ReactiveCocoa,jsslai/ReactiveCocoa,Khan/ReactiveCocoa,leelili/ReactiveCocoa,huiping192/ReactiveCocoa,jrmiddle/ReactiveCocoa,yizzuide/ReactiveCocoa,shuxiashusheng/ReactiveCocoa,jeelun/ReactiveCocoa,Pingco/ReactiveCocoa,xumaolin/ReactiveCocoa,zhiwen1024/ReactiveCocoa,pzw224/ReactiveCocoa,Remitly/ReactiveCocoa,llb1119/test,clg0118/ReactiveCocoa,libiao88/ReactiveCocoa,clg0118/ReactiveCocoa,zzqiltw/ReactiveCocoa,tzongw/ReactiveCocoa,msdgwzhy6/ReactiveCocoa,emodeqidao/ReactiveCocoa,libiao88/ReactiveCocoa,leichunfeng/ReactiveCocoa,AllanChen/ReactiveCocoa,KJin99/ReactiveCocoa,kevin-zqw/ReactiveCocoa,RuiAAPeres/ReactiveCocoa,Carthage/ReactiveCocoa,llb1119/test,luerhouhou/ReactiveCocoa,yangyangluoluo/ReactiveCocoa,shaohung001/ReactiveCocoa,Juraldinio/ReactiveCocoa,valleyman86/ReactiveCocoa,ohwutup/ReactiveCocoa,JackLian/ReactiveCocoa,cstars135/ReactiveCocoa,eliperkins/ReactiveCocoa,richeterre/ReactiveCocoa,sandyway/ReactiveCocoa,hj3938/ReactiveCocoa,nickcheng/ReactiveCocoa,stupidfive/ReactiveCocoa,PSPDFKit-labs/ReactiveCocoa,JohnJin007/ReactiveCocoa,alvinvarghese/ReactiveCocoa,loupman/ReactiveCocoa,j364960953/ReactiveCocoa,Liquidsoul/ReactiveCocoa,ddc391565320/ReactiveCocoa,335g/ReactiveCocoa,nickcheng/ReactiveCocoa,ikesyo/ReactiveCocoa,cogddo/ReactiveCocoa,qq644531343/ReactiveCocoa,lixar/ReactiveCocoa,CQXfly/ReactiveCocoa,CCOOOOLL/ReactiveCocoa,xiaobing2007/ReactiveCocoa,swizzlr/ReactiveCocoa,hbucius/ReactiveCocoa,tornade0913/ReactiveCocoa,yangshengchaoios/ReactiveCocoa,ceekayel/ReactiveCocoa,fhchina/ReactiveCocoa,KuPai32G/ReactiveCocoa,howandhao/ReactiveCocoa,esttorhe/ReactiveCocoa,gengjf/ReactiveCocoa,goodheart/ReactiveCocoa,ohwutup/ReactiveCocoa,icepy/ReactiveCocoa,xulibao/ReactiveCocoa,leelili/ReactiveCocoa,dachaoisme/ReactiveCocoa,mattpetters/ReactiveCocoa,juliangrosshauser/ReactiveCocoa,juliangrosshauser/ReactiveCocoa,zhigang1992/ReactiveCocoa,towik/ReactiveCocoa,ioshger0125/ReactiveCocoa,andersio/ReactiveCocoa,GuitarPlayer-Ma/ReactiveCocoa,ztchena/ReactiveCocoa,FelixYin66/ReactiveCocoa,yonekawa/ReactiveCocoa,Khan/ReactiveCocoa,itschaitanya/ReactiveCocoa,mxxiv/ReactiveCocoa