Fixed both history preview url, and always format with /1 if no rev.
Fixed both history preview url, and always format with /1 if no rev.

Note that there's a bug ref #172

arcseldon/jsbin,johnmichel/jsbin,juliankrispel/jsbin,jwdallas/jsbin,jasonsanjose/jsbin-app,martinvd/jsbin,thsunmy/jsbin,svacha/jsbin,knpwrs/jsbin,fgrillo21/NPA-Exam,kentcdodds/jsbin,IvanSanchez/jsbin,jwdallas/jsbin,Hamcha/jsbin,carolineartz/jsbin,dhval/jsbin,fend-classroom/jsbin,ilyes14/jsbin,mlucool/jsbin,kirjs/jsbin,ctide/jsbin,mdo/jsbin,fend-classroom/jsbin,knpwrs/jsbin,roman01la/jsbin,vipulnsward/jsbin,simonThiele/jsbin,Hamcha/jsbin,y3sh/jsbin-fork,johnmichel/jsbin,kentcdodds/jsbin,KenPowers/jsbin,dedalik/jsbin,mingzeke/jsbin,ctide/jsbin,late-warrior/jsbin,peterblazejewicz/jsbin,jsbin/jsbin,HeroicEric/jsbin,kirjs/jsbin,mlucool/jsbin,eggheadio/jsbin,saikota/jsbin,yize/jsbin,thsunmy/jsbin,minwe/jsbin,HeroicEric/jsbin,peterblazejewicz/jsbin,martinvd/jsbin,dennishu001/jsbin,IveWong/jsbin,carolineartz/jsbin,IvanSanchez/jsbin,francoisp/jsbin,knpwrs/jsbin,remotty/jsbin,eggheadio/jsbin,AverageMarcus/jsbin,saikota/jsbin,dhval/jsbin,arcseldon/jsbin,AverageMarcus/jsbin,KenPowers/jsbin,IveWong/jsbin,y3sh/jsbin-fork,filamentgroup/jsbin,KenPowers/jsbin,yize/jsbin,minwe/jsbin,filamentgroup/jsbin,mcanthony/jsbin,mingzeke/jsbin,ilyes14/jsbin,dedalik/jsbin,late-warrior/jsbin,mcanthony/jsbin,digideskio/jsbin,roman01la/jsbin,dennishu001/jsbin,jsbin/jsbin,jamez14/jsbin,Freeformers/jsbin,simonThiele/jsbin,yohanboniface/jsbin,pandoraui/jsbin,pandoraui/jsbin,svacha/jsbin,fgrillo21/NPA-Exam,nitaku/jervis,blesh/jsbin,jasonsanjose/jsbin-app,digideskio/jsbin,francoisp/jsbin,jamez14/jsbin,juliankrispel/jsbin,Freeformers/jsbin,vipulnsward/jsbin,yohanboniface/jsbin