Move Ember dependency loading into head.
Move Ember dependency loading into head.

Without this change the first run of any ember application fails
everytime (since `Ember` isn't defined).

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