auto merge of #610 : metajack/servo/fix-reftest, r=pcwalton
auto merge of #610 : metajack/servo/fix-reftest, r=pcwalton

This adds a sha1 hash to the output filenames based on the test. Rust runs
tests in parallel by default, so the test files were stomping on each other.

rentongzhang/servo,paulrouget/servo,codemac/servo,jgraham/servo,szeged/servo,ruud-v-a/servo,nick-thompson/servo,KiChjang/servo,emilio/servo,s142857/servo,pyecs/servo,rentongzhang/servo,wartman4404/servo,metajack/servo,tafia/servo,cbrewster/servo,Shraddha512/servo,seanmonstar/servo,zentner-kyle/servo,hyowon/servo,rixrix/servo,froydnj/servo,szeged/servo,s142857/servo,s142857/servo,chotchki/servo,AnthonyBroadCrawford/servo,tafia/servo,caldwell/servo,boghison/servo,tafia/servo,splav/servo,ruud-v-a/servo,saneyuki/servo,KiChjang/servo,GreenRecycleBin/servo,youprofit/servo,peterjoel/servo,dhananjay92/servo,tempbottle/servo,ruud-v-a/servo,Adenilson/prototype-viewing-distance,GyrosOfWar/servo,srbhklkrn/SERVOENGINE,AnthonyBroadCrawford/servo,metajack/servo,DominoTree/servo,karlito40/servo,huonw/servo,thiagopnts/servo,meh/servo,Shraddha512/servo,evilpie/servo,larsbergstrom/servo,peterjoel/servo,CJ8664/servo,dmarcos/servo,szeged/servo,steveklabnik/servo,nerith/servo,peterjoel/servo,owaspjocur/servo,splav/servo,vks/servo,michaelwu/servo,wartman4404/servo,srbhklkrn/SERVOENGINE,mt2d2/servo,larsbergstrom/servo,walac/servo,jimberlage/servo,nnethercote/servo,kindersung/servo,tempbottle/servo,ruud-v-a/servo,dati91/servo,saneyuki/servo,cbrewster/servo,j3parker/servo,wartman4404/servo,g-k/servo,pyfisch/servo,Shraddha512/servo,Aalhad/CanvasRenderingContext2DMozilla,fiji-flo/servo,upsuper/servo,jdramani/servo,tempbottle/servo,echochamber/servo,karlito40/servo,jimberlage/servo,mbrubeck/servo,nick-thompson/servo,aidanhs/servo,froydnj/servo,tschneidereit/servo,notriddle/servo,peterjoel/servo,seanmonstar/servo,evilpie/servo,dati91/servo,rentongzhang/servo,mukilan/servo,avadacatavra/servo,zhangjunlei26/servo,wartman4404/servo,Aalhad/CanvasRenderingContext2DMozilla,splav/servo,shrenikgala/servo,metajack/servo,indykish/servo,DominoTree/servo,steveklabnik/servo,upsuper/servo,wpgallih/servo,WriterOfAlicrow/servo,fiji-flo/servo,CJ8664/servo,ConnorGBrewster/servo,pcwalton/servo,RenaudParis/servo,emilio/servo,anthgur/servo,froydnj/servo,pyfisch/servo,codemac/servo,jgraham/servo,mukilan/servo,tafia/servo,dmarcos/servo,youprofit/servo,pgonda/servo,nnethercote/servo,dagnir/servo,RenaudParis/servo,hyowon/servo,mrobinson/servo,RenaudParis/servo,huonw/servo,dsandeephegde/servo,g-k/servo,nrc/servo,srbhklkrn/SERVOENGINE,jdramani/servo,nrc/servo,bjwbell/servo,pyecs/servo,splav/servo,shrenikgala/servo,Adenilson/prototype-viewing-distance,walac/servo,chotchki/servo,brson/servo,boghison/servo,notriddle/servo,mt2d2/servo,dati91/servo,paulrouget/servo,emilio/servo,DominoTree/servo,larsbergstrom/servo,sadmansk/servo,runarberg/servo,jimberlage/servo,ryancanhelpyou/servo,nick-thompson/servo,RenaudParis/servo,snf/servo,walac/servo,indykish/servo,AnthonyBroadCrawford/servo,michaelwu/servo,seanmonstar/servo,aweinstock314/servo,brendandahl/servo,jgraham/servo,brendandahl/servo,thiagopnts/servo,dsandeephegde/servo,pyecs/servo,jdramani/servo,vks/servo,seanmonstar/servo,avadacatavra/servo,szeged/servo,vks/servo,luniv/servo,GyrosOfWar/servo,notriddle/servo,KiChjang/servo,snf/servo,deokjinkim/servo,avadacatavra/servo,indykish/servo,saratang/servo,aidanhs/servo,nnethercote/servo,youprofit/servo,rixrix/servo,owaspjocur/servo,Aalhad/CanvasRenderingContext2DMozilla,WriterOfAlicrow/servo,anthgur/servo,ConnorGBrewster/servo,anthgur/servo,paulrouget/servo,metajack/servo,michaelwu/servo,pyfisch/servo,boghison/servo,brendandahl/servo,aidanhs/servo,indykish/servo,dvberkel/servo,srbhklkrn/SERVOENGINE,eddyb/servo,pcwalton/servo,vks/servo,steveklabnik/servo,walac/servo,cbrewster/servo,nick-thompson/servo,rixrix/servo,jdramani/servo,caldwell/servo,peterjoel/servo,saratang/servo,dhananjay92/servo,brson/servo,paulrouget/servo,karlito40/servo,indykish/servo,nnethercote/servo,dati91/servo,walac/servo,snf/servo,CJ8664/servo,echochamber/servo,tafia/servo,rnestler/servo,mbrubeck/servo,tempbottle/servo,SimonSapin/servo,upsuper/servo,mt2d2/servo,pyfisch/servo,CJ8664/servo,wartman4404/servo,paulrouget/servo,ConnorGBrewster/servo,runarberg/servo,GreenRecycleBin/servo,saneyuki/servo,bfrohs/servo,mdibaiee/servo,ConnorGBrewster/servo,nerith/servo,SimonSapin/servo,wpgallih/servo,SimonSapin/servo,indykish/servo,echochamber/servo,nick-thompson/servo,ryancanhelpyou/servo,zhangjunlei26/servo,nrc/servo,splav/servo,mattnenterprise/servo,upsuper/servo,jlegendary/servo,brendandahl/servo,evilpie/servo,shrenikgala/servo,peterjoel/servo,A-deLuna/servo,pcwalton/servo,tempbottle/servo,dagnir/servo,Aalhad/CanvasRenderingContext2DMozilla,avadacatavra/servo,vks/servo,jlegendary/servo,zhangjunlei26/servo,echochamber/servo,j3parker/servo,eddyb/servo,GreenRecycleBin/servo,ryancanhelpyou/servo,RenaudParis/servo,RenaudParis/servo,michaelwu/servo,samfoo/servo,samfoo/servo,pcwalton/servo,pyecs/servo,mdibaiee/servo,splav/servo,aweinstock314/servo,nnethercote/servo,dvberkel/servo,nrc/servo,kindersung/servo,larsbergstrom/servo,deokjinkim/servo,GyrosOfWar/servo,sadmansk/servo,emilio/servo,brson/servo,zentner-kyle/servo,ConnorGBrewster/servo,notriddle/servo,caldwell/servo,karlito40/servo,nick-thompson/servo,huonw/servo,Aalhad/CanvasRenderingContext2DMozilla,eddyb/servo,rentongzhang/servo,pgonda/servo,brendandahl/servo,pyfisch/servo,indykish/servo,echochamber/servo,canaltinova/servo,paulrouget/servo,bfrohs/servo,jlegendary/servo,zentner-kyle/servo,dsandeephegde/servo,bjwbell/servo,larsbergstrom/servo,cbrewster/servo,bfrohs/servo,avadacatavra/servo,nnethercote/servo,snf/servo,karlito40/servo,peterjoel/servo,tafia/servo,szeged/servo,jdramani/servo,codemac/servo,s142857/servo,bjwbell/servo,luniv/servo,mt2d2/servo,notriddle/servo,aweinstock314/servo,dati91/servo,froydnj/servo,upsuper/servo,mt2d2/servo,pyecs/servo,sadmansk/servo,g-k/servo,Shraddha512/servo,g-k/servo,zentner-kyle/servo,bfrohs/servo,DominoTree/servo,tschneidereit/servo,splav/servo,dagnir/servo,avadacatavra/servo,chotchki/servo,larsbergstrom/servo,snf/servo,Adenilson/prototype-viewing-distance,nrc/servo,sadmansk/servo,Adenilson/prototype-viewing-distance,fiji-flo/servo,akosel/servo,indykish/servo,rentongzhang/servo,dati91/servo,juzer10/servo,boghison/servo,dsandeephegde/servo,dvberkel/servo,codemac/servo,juzer10/servo,CJ8664/servo,dati91/servo,michaelwu/servo,rnestler/servo,mt2d2/servo,pgonda/servo,avadacatavra/servo,kindersung/servo,canaltinova/servo,caldwell/servo,hyowon/servo,jimberlage/servo,nerith/servo,upsuper/servo,srbhklkrn/SERVOENGINE,DominoTree/servo,dsandeephegde/servo,meh/servo,nnethercote/servo,thiagopnts/servo,j3parker/servo,dvberkel/servo,AnthonyBroadCrawford/servo,echochamber/servo,deokjinkim/servo,srbhklkrn/SERVOENGINE,mrobinson/servo,paulrouget/servo,Shraddha512/servo,GreenRecycleBin/servo,eddyb/servo,SimonSapin/servo,canaltinova/servo,brson/servo,luniv/servo,rixrix/servo,aweinstock314/servo,GreenRecycleBin/servo,juzer10/servo,dagnir/servo,ruud-v-a/servo,g-k/servo,paulrouget/servo,aweinstock314/servo,bjwbell/servo,kindersung/servo,rnestler/servo,larsbergstrom/servo,evilpie/servo,owaspjocur/servo,fiji-flo/servo,brson/servo,runarberg/servo,zhangjunlei26/servo,ryancanhelpyou/servo,tschneidereit/servo,rixrix/servo,canaltinova/servo,avadacatavra/servo,fiji-flo/servo,Aalhad/CanvasRenderingContext2DMozilla,fiji-flo/servo,sadmansk/servo,codemac/servo,boghison/servo,youprofit/servo,bjwbell/servo,walac/servo,srbhklkrn/SERVOENGINE,caldwell/servo,KiChjang/servo,metajack/servo,thiagopnts/servo,GreenRecycleBin/servo,indykish/servo,j3parker/servo,runarberg/servo,saneyuki/servo,dhananjay92/servo,WriterOfAlicrow/servo,RenaudParis/servo,luniv/servo,metajack/servo,A-deLuna/servo,saneyuki/servo,mbrubeck/servo,brson/servo,mattnenterprise/servo,caldwell/servo,jimberlage/servo,mbrubeck/servo,WriterOfAlicrow/servo,juzer10/servo,notriddle/servo,aidanhs/servo,evilpie/servo,aweinstock314/servo,mattnenterprise/servo,dsandeephegde/servo,huonw/servo,DominoTree/servo,WriterOfAlicrow/servo,ruud-v-a/servo,thiagopnts/servo,pyfisch/servo,shrenikgala/servo,bjwbell/servo,GreenRecycleBin/servo,nick-thompson/servo,caldwell/servo,emilio/servo,rixrix/servo,tschneidereit/servo,runarberg/servo,ConnorGBrewster/servo,cbrewster/servo,A-deLuna/servo,jimberlage/servo,szeged/servo,pyecs/servo,owaspjocur/servo,mrobinson/servo,pyfisch/servo,ConnorGBrewster/servo,zhangjunlei26/servo,tschneidereit/servo,samfoo/servo,seanmonstar/servo,evilpie/servo,GyrosOfWar/servo,dagnir/servo,Adenilson/prototype-viewing-distance,thiagopnts/servo,kindersung/servo,nerith/servo,WriterOfAlicrow/servo,mdibaiee/servo,eddyb/servo,mrobinson/servo,j3parker/servo,mdibaiee/servo,j3parker/servo,KiChjang/servo,szeged/servo,tschneidereit/servo,steveklabnik/servo,peterjoel/servo,zhangjunlei26/servo,A-deLuna/servo,rixrix/servo,boghison/servo,codemac/servo,A-deLuna/servo,nnethercote/servo,KiChjang/servo,dhananjay92/servo,GyrosOfWar/servo,mt2d2/servo,seanmonstar/servo,rixrix/servo,pyfisch/servo,emilio/servo,pgonda/servo,samfoo/servo,owaspjocur/servo,AnthonyBroadCrawford/servo,upsuper/servo,DominoTree/servo,steveklabnik/servo,emilio/servo,juzer10/servo,akosel/servo,nerith/servo,aidanhs/servo,chotchki/servo,peterjoel/servo,jimberlage/servo,upsuper/servo,pcwalton/servo,sadmansk/servo,mbrubeck/servo,pyecs/servo,mdibaiee/servo,jlegendary/servo,wartman4404/servo,mrobinson/servo,jdramani/servo,wartman4404/servo,evilpie/servo,zhangjunlei26/servo,saneyuki/servo,peterjoel/servo,anthgur/servo,shrenikgala/servo,kindersung/servo,g-k/servo,brendandahl/servo,saratang/servo,splav/servo,akosel/servo,rentongzhang/servo,wpgallih/servo,huonw/servo,samfoo/servo,rnestler/servo,GreenRecycleBin/servo,chotchki/servo,pcwalton/servo,steveklabnik/servo,boghison/servo,chotchki/servo,juzer10/servo,cbrewster/servo,hyowon/servo,kindersung/servo,nerith/servo,zhangjunlei26/servo,codemac/servo,bjwbell/servo,deokjinkim/servo,ryancanhelpyou/servo,tschneidereit/servo,s142857/servo,saratang/servo,nnethercote/servo,aidanhs/servo,akosel/servo,dmarcos/servo,paulrouget/servo,KiChjang/servo,mbrubeck/servo,CJ8664/servo,dmarcos/servo,Adenilson/prototype-viewing-distance,anthgur/servo,mukilan/servo,saneyuki/servo,KiChjang/servo,hyowon/servo,huonw/servo,tafia/servo,canaltinova/servo,ryancanhelpyou/servo,szeged/servo,evilpie/servo,rnestler/servo,jgraham/servo,nrc/servo,Shraddha512/servo,mattnenterprise/servo,deokjinkim/servo,emilio/servo,dmarcos/servo,anthgur/servo,thiagopnts/servo,SimonSapin/servo,larsbergstrom/servo,GreenRecycleBin/servo,notriddle/servo,mbrubeck/servo,mdibaiee/servo,meh/servo,karlito40/servo,froydnj/servo,SimonSapin/servo,AnthonyBroadCrawford/servo,larsbergstrom/servo,luniv/servo,splav/servo,sadmansk/servo,luniv/servo,anthgur/servo,dhananjay92/servo,tempbottle/servo,GyrosOfWar/servo,aidanhs/servo,dvberkel/servo,mdibaiee/servo,meh/servo,snf/servo,canaltinova/servo,runarberg/servo,huonw/servo,rnestler/servo,ryancanhelpyou/servo,pyfisch/servo,youprofit/servo,echochamber/servo,snf/servo,mukilan/servo,eddyb/servo,pgonda/servo,jlegendary/servo,hyowon/servo,brendandahl/servo,dsandeephegde/servo,SimonSapin/servo,youprofit/servo,larsbergstrom/servo,wpgallih/servo,mattnenterprise/servo,samfoo/servo,dmarcos/servo,hyowon/servo,jlegendary/servo,saratang/servo,jgraham/servo,wpgallih/servo,dvberkel/servo,meh/servo,pgonda/servo,pyfisch/servo,vks/servo,zentner-kyle/servo,splav/servo,michaelwu/servo,A-deLuna/servo,bfrohs/servo,nrc/servo,akosel/servo,saratang/servo,ConnorGBrewster/servo,fiji-flo/servo,emilio/servo,GyrosOfWar/servo,youprofit/servo,walac/servo,nnethercote/servo,shrenikgala/servo,mukilan/servo,shrenikgala/servo,dati91/servo,Adenilson/prototype-viewing-distance,canaltinova/servo,s142857/servo,cbrewster/servo,jdramani/servo,dsandeephegde/servo,fiji-flo/servo,pgonda/servo,AnthonyBroadCrawford/servo,DominoTree/servo,froydnj/servo,WriterOfAlicrow/servo,DominoTree/servo,s142857/servo,rixrix/servo,thiagopnts/servo,jgraham/servo,mattnenterprise/servo,saratang/servo,mattnenterprise/servo,CJ8664/servo,rnestler/servo,jimberlage/servo,paulrouget/servo,deokjinkim/servo,deokjinkim/servo,vks/servo,j3parker/servo,szeged/servo,g-k/servo,rnestler/servo,KiChjang/servo,CJ8664/servo,jlegendary/servo,szeged/servo,wpgallih/servo,nerith/servo,zentner-kyle/servo,A-deLuna/servo,mattnenterprise/servo,samfoo/servo,karlito40/servo,eddyb/servo,Shraddha512/servo,dhananjay92/servo,bfrohs/servo,evilpie/servo,dagnir/servo,dmarcos/servo,jgraham/servo,dhananjay92/servo,DominoTree/servo,saneyuki/servo,akosel/servo,juzer10/servo,mukilan/servo,meh/servo,jimberlage/servo,wpgallih/servo,rentongzhang/servo,canaltinova/servo,dagnir/servo,runarberg/servo,akosel/servo,KiChjang/servo,notriddle/servo,saneyuki/servo,notriddle/servo,luniv/servo,wpgallih/servo,mbrubeck/servo,meh/servo,zhangjunlei26/servo,emilio/servo,mrobinson/servo,notriddle/servo,anthgur/servo,sadmansk/servo,owaspjocur/servo,wpgallih/servo,steveklabnik/servo,SimonSapin/servo,tempbottle/servo,dvberkel/servo,aweinstock314/servo,saneyuki/servo,zentner-kyle/servo,cbrewster/servo,eddyb/servo