Add URL prefixes for Login and Edit buttons
Add URL prefixes for Login and Edit buttons

(part of unmerged patch from https://github.com/jsbin/jsbin/pull/1450)

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