Guard against URL components starting with slash
Guard against URL components starting with slash

If you set url: '/foo' or namespace: '/api', you get URLs with two
leading slashes, which then are interpreted protocol-relative
(http://foo). This is incredibly confusing, so this patch adds
assertions to guard against it.

basho/ember-data,slindberg/data,gkaran/data,zoeesilcock/data,flowjzh/data,jgwhite/data,workmanw/data,sebastianseilund/data,eriktrom/data,InboxHealth/data,dustinfarris/data,simaob/data,tarzan/data,Eric-Guo/data,gniquil/data,faizaanshamsi/data,ryanpatrickcook/data,gniquil/data,intuitivepixel/data,Globegitter/ember-data-evolution,simaob/data,arenoir/data,Turbo87/ember-data,topaxi/data,rtablada/data,vikram7/data,kappiah/data,thaume/data,bf4/data,intuitivepixel/data,bf4/data,seanpdoyle/data,hibariya/data,courajs/data,Turbo87/ember-data,whatthewhat/data,whatthewhat/data,slindberg/data,PrecisionNutrition/data,flowjzh/data,heathharrelson/data,tchak/data,kimroen/data,gabriel-letarte/data,duggiefresh/data,arenoir/data,minasmart/data,wecc/data,flowjzh/data,jgwhite/data,seanpdoyle/data,Kuzirashi/data,Globegitter/ember-data-evolution,swarmbox/data,simaob/data,danmcclain/data,H1D/data,BBLN/data,mphasize/data,ryanpatrickcook/data,tstirrat/ember-data,bcardarella/data,heathharrelson/data,BookingSync/data,stefanpenner/data,Robdel12/data,k-fish/data,thaume/data,fsmanuel/data,davidpett/data,hibariya/data,radiumsoftware/data,rtablada/data,ryanpatrickcook/data,Robdel12/data,mphasize/data,splattne/data,EmberSherpa/data,bcardarella/data,arenoir/data,greyhwndz/data,martndemus/data,HeroicEric/data,H1D/data,Kuzirashi/data,InboxHealth/data,andrejunges/data,minasmart/data,minasmart/data,rwjblue/data,usecanvas/data,seanpdoyle/data,fsmanuel/data,thaume/data,splattne/data,knownasilya/data,martndemus/data,nickiaconis/data,BookingSync/data,hibariya/data,whatthewhat/data,workmanw/data,webPapaya/data,jmurphyau/data,EmberSherpa/data,FinSync/ember-data,bcardarella/data,flowjzh/data,tstirrat/ember-data,faizaanshamsi/data,tarzan/data,yaymukund/data,PrecisionNutrition/data,jmurphyau/data,swarmbox/data,bf4/data,in4mates/ember-data,fsmanuel/data,greyhwndz/data,Kuzirashi/data,tonywok/data,Robdel12/data,sammcgrail/data,H1D/data,BBLN/data,stefanpenner/data,usecanvas/data,knownasilya/data,Addepar/ember-data,trisrael/em-data,sammcgrail/data,tarzan/data,yaymukund/data,rtablada/data,fpauser/data,martndemus/data,Turbo87/ember-data,PrecisionNutrition/data,EmberSherpa/data,BBLN/data,kappiah/data,acburdine/data,teddyzeenny/data,InboxHealth/data,zoeesilcock/data,bf4/data,teddyzeenny/data,wecc/data,zoeesilcock/data,vikram7/data,duggiefresh/data,thaume/data,duggiefresh/data,faizaanshamsi/data,pdud/data,vikram7/data,sebweaver/data,Addepar/ember-data,workmanw/data,danmcclain/data,FinSync/ember-data,acburdine/data,duggiefresh/data,splattne/data,fsmanuel/data,courajs/data,slindberg/data,yaymukund/data,HeroicEric/data,kimroen/data,mphasize/data,simaob/data,heathharrelson/data,sebastianseilund/data,gabriel-letarte/data,topaxi/data,courajs/data,usecanvas/data,sebastianseilund/data,intuitivepixel/data,rtablada/data,sebweaver/data,martndemus/data,EmberSherpa/data,danmcclain/data,Turbo87/ember-data,sammcgrail/data,kappiah/data,funtusov/data,Eric-Guo/data,greyhwndz/data,pdud/data,funtusov/data,eriktrom/data,davidpett/data,k-fish/data,nickiaconis/data,radiumsoftware/data,H1D/data,funtusov/data,sammcgrail/data,sebweaver/data,faizaanshamsi/data,XrXr/data,kappiah/data,davidpett/data,offirgolan/data,topaxi/data,BBLN/data,FinSync/ember-data,acburdine/data,webPapaya/data,XrXr/data,FinSync/ember-data,eriktrom/data,sandstrom/ember-data,basho/ember-data,in4mates/ember-data,sebweaver/data,wecc/data,offirgolan/data,gabriel-letarte/data,jgwhite/data,pdud/data,gniquil/data,intuitivepixel/data,tarzan/data,sandstrom/ember-data,k-fish/data,bcardarella/data,minasmart/data,stefanpenner/data,stefanpenner/data,Kuzirashi/data,mphasize/data,knownasilya/data,gkaran/data,jmurphyau/data,heathharrelson/data,funtusov/data,topaxi/data,offirgolan/data,workmanw/data,jgwhite/data,BookingSync/data,XrXr/data,InboxHealth/data,greyhwndz/data,HeroicEric/data,jmurphyau/data,webPapaya/data,PrecisionNutrition/data,whatthewhat/data,hjdivad/data,ryanpatrickcook/data,andrejunges/data,tonywok/data,sebastianseilund/data,lostinpatterns/data,vikram7/data,gkaran/data,tonywok/data,swarmbox/data,lostinpatterns/data,dustinfarris/data,fpauser/data,yaymukund/data,acburdine/data,tstirrat/ember-data,tchak/data,nickiaconis/data,seanpdoyle/data,Eric-Guo/data,rwjblue/data,courajs/data,Addepar/ember-data,gabriel-letarte/data,fpauser/data,HeroicEric/data,fpauser/data,lostinpatterns/data,nickiaconis/data,hjdivad/data,lostinpatterns/data,Robdel12/data,zoeesilcock/data,webPapaya/data,dustinfarris/data,splattne/data,tonywok/data,swarmbox/data,andrejunges/data,in4mates/ember-data,trisrael/em-data,davidpett/data,k-fish/data,dustinfarris/data,hibariya/data,offirgolan/data,Eric-Guo/data,kimroen/data,gniquil/data,usecanvas/data,danmcclain/data,gkaran/data,tstirrat/ember-data,XrXr/data,trisrael/em-data,eriktrom/data,wecc/data,BookingSync/data,andrejunges/data,arenoir/data,pdud/data