Update backbone.js
Update backbone.js

In `Events.once` we can streamline the final statements `this.on(...); return this;` into `return this.on(...)`, as `Events.on` also returns `this`. Saves a row for a very slight loss of readability.

Same thing applies in the `_.each` loop where we set up the IoC versions of `on` and `once`.
moimikey/backbone,ThisIsManta/Backbone,alekskorolev/lightbones,Niades/backbone,Flip120/backbone,sunday-star/backbone,jmeas/backbone,youprofit/backbone,tadwhitaker/backbone,jewsroch/backbone,ereddate/backbone,rashmisajjan/backbone,nvoron23/backbone,anhtholee/backbone,ntgn81/backbone,chyeh727/backbone,ThisIsManta/Backbone,zhangwei001/backbone,tzkKrbys/backbone,webcoding/backbone,gitterHQ/backbone,wakanpaladin/mybackbone,streamablevideo/backbone,zdespolit/backbone,timebackzhou/backbone,dak/backbone,elancom/backbone,Flip120/backbone,dillonforrest/backbone-df,lastjune/backbone,Aplopio/backbone,LovelyL25/backbone.js,alekskorolev/lightbones,anhtholee/backbone,mrblueblue/backbone,craigmichaelmartin/backbone,closeio/backbone,leimd/backbone,elma-cao/backbone,feychenie/backbone,honger05/backbone,guigrpa/backbone,nikolas/backbone,ywenjinlin/backbone,embarknow/backbone,nvoron23/backbone,batigoal1980/backbone_example,dcheepurupalli/backbone,mmolinastudio/backbone,jmeas/backbone,zhangdimelody/backbone,Sachin-Ganesh/backbone,oss-practice/backbone,mpapp/backbone,JesseQin/backbone,megawac/backbone,DannyDelott/backbone,getshuvo/backbone,trizko/backbone,elma-cao/backbone,IsoldaJS/isolda-pubsub,7213/backbone,batigoal1980/backbone_example,Khan/backbone,udhayam/backbone,platinumazure/backbone,ereddate/backbone,darrrk/backbone,guahanweb/backbone,jungjung917/backbone,heroazure/backbone,wangdahoo/backbone,cgvarela/backbone,maryrosecook/backbone-df,akre54/backbone,sunday-star/backbone,howtolearntocode/backbone,tibic/backbone,liudianpeng/backbone,GerHobbelt/backbone,wangcan2014/backbone,leimd/backbone,Bug2014/backbone,wxmfront/backbone,JesseQin/backbone,kuychaco/backbone,howtolearntocode/backbone,tibic/backbone,wushuyi/backbone,rjz/boneless,premkumargithub/backbone,linalu1/backbone,GrimDerp/backbone,FormidableLabs/backbone,cailong1028/backbone,neocotic/hipbone,gmaclennan/backbone,GrimDerp/backbone,premkumargithub/backbone,FishbaitHarry/backbone,Bug2014/backbone,amitpatange88/backbonejs,FishbaitHarry/backbone,dak/backbone,DannyDelott/backbone,nikolas/backbone,moccen/backbone,wakanpaladin/mybackbone,Krasnyanskiy/backbone,sueyeh/backbone,jashkenas/backbone,au-phiware/backbone,fanhc019/backbone,componentizr/backbone,antoniogarrote/backbone,Sachin-Ganesh/backbone,GerHobbelt/backbone,tgriesser/backbone,Aplopio/backbone,linalu1/backbone,ppker/backbone,zgl2007dj/backbone,huanglp47/backbone,lujocom/backbone,wushuyi/backbone,Diwahars/backbone,darrrk/backbone,lastjune/backbone,LovelyL25/backbone.js,dillonforrest/backbone-df,jridgewell/backbone,braddunbar/backbone,gdi2290/backbone,tzkKrbys/backbone,jridgewell/backbone,ThiagoGarciaAlves/backbone,honger05/backbone,maryrosecook/backbone-df,vincent1988/backbone,trizko/backbone,elancom/backbone,webapp/library,neocotic/hipbone,ppker/backbone,amitpatange88/backbonejs,sitexa/backbone,yuhualingfeng/backbone,lujocom/backbone,virtru-components/backbone,ridixcr/backbone,Diwahars/backbone,chyeh727/backbone,vin100bk/backbone,ebsco/backbone,pandoraui/backbone,platinumazure/backbone,ywenjinlin/backbone,youprofit/backbone,dcheepurupalli/backbone,pandoraui/backbone,Khan/backbone,Krasnyanskiy/backbone,zhoufan879/backbone,aihua/backbone,aihua/backbone,ntgn81/backbone,sueyeh/backbone,gougouGet/backbone,hugohua/backbone,zhangdimelody/backbone,jashkenas/backbone,sumyfly/backbone,jungjung917/backbone,webapp/library,yuhualingfeng/backbone,Connectlegendary/backbone,Connectlegendary/backbone,heroazure/backbone,jewsroch/backbone,maryrosecook/backbone-df,Akkuma/backbone,ohbarye/backbone,IsoldaJS/isolda-models,zhangwei001/backbone,zdespolit/backbone,sumyfly/backbone,jstrimpel/backbone,braddunbar/backbone,tadwhitaker/backbone,au-phiware/backbone,mmolinastudio/backbone,zgl2007dj/backbone,npmcomponent/jashkenas-backbone,feychenie/backbone,dillonforrest/backbone-df,ebsco/backbone,guahanweb/backbone,cailong1028/backbone,liudianpeng/backbone,mrblueblue/backbone,ridixcr/backbone,wjb12/backbone,paulfalgout/backbone,luffy94608/backbone,vincent1988/backbone,akre54/backbone,embarknow/backbone,jstrimpel/backbone,zhoufan879/backbone,streamablevideo/backbone,luffy94608/backbone,vin100bk/backbone,craigmichaelmartin/backbone,amdjs/backbone,webcoding/backbone,timebackzhou/backbone,udhayam/backbone,yawenl/backbone,cgvarela/backbone,gmaclennan/backbone,jordansexton/backboner,moccen/backbone,ohbarye/backbone,wxmfront/backbone,Khan/backbone,closeio/backbone,wjb12/backbone,wangcan2014/backbone,kuychaco/backbone,sitexa/backbone,yawenl/backbone,fanhc019/backbone,Aplopio/backbone,huanglp47/backbone,gougouGet/backbone,wangdahoo/backbone,ThiagoGarciaAlves/backbone,7213/backbone,rashmisajjan/backbone,getshuvo/backbone,moimikey/backbone,jasoncbautista/backboneX,Niades/backbone,paulfalgout/backbone