in build.sh, retry builds if it looks like xcodebuild crashed.
in build.sh, retry builds if it looks like xcodebuild crashed.

We've seen both Xcode 4 and Xcode 5 crash while building xctool.  To
mitigate, we're wrapping our build in some retry logic.

n054/xctool,kernandreas/xctool,facebook/xctool,AutoScout24/xctool,adamjernst/xctool,1yvT0s/xctool,duk42111/xctool,LegNeato/xctool,kernandreas/xctool,SuPair/xctool,yaoxiaoyong/xctool,bgertzfield/xctool,ACChe/xctool,facebook/xctool,PSPDFKit-labs/xctool,AutoScout24/xctool,agreco/xctool,theiren46/xctool,githubdelegate/xctool,PSPDFKit-labs/xctool,jspahrsummers/xctool,Monits/xctool,blighli/xctool,kamoljan/xctool,bgertzfield/xctool,jspahrsummers/xctool,AutoScout24/xctool,kamoljan/xctool,agreco/xctool,LegNeato/xctool,ACChe/xctool,PSPDFKit-labs/xctool,Monits/xctool,githubdelegate/xctool,leopardpan/xctool,modulexcite/xctool,PSPDFKit-labs/xctool,bhamiltoncx/xctool,ekingo/xctool,bgertzfield/xctool,yaoxiaoyong/xctool,facebook/xctool,githubdelegate/xctool,trello/xctool,lpios/xctool,ekingo/xctool,n054/xctool,AutoScout24/xctool,soundcloud/xctool,ekingo/xctool,dvor/xctool,githubdelegate/xctool,Monits/xctool,kamoljan/xctool,lpios/xctool,bhamiltoncx/xctool,ACChe/xctool,duk42111/xctool,ACChe/xctool,lpios/xctool,LegNeato/xctool,lpios/xctool,soundcloud/xctool,kamoljan/xctool,n054/xctool,n054/xctool,n054/xctool,modulexcite/xctool,jspahrsummers/xctool,bgertzfield/xctool,bhamiltoncx/xctool,Richardlihui/xctool,soundcloud/xctool,bhamiltoncx/xctool,leopardpan/xctool,blighli/xctool,adamjernst/xctool,yaoxiaoyong/xctool,dvor/xctool,ACChe/xctool,blighli/xctool,soundcloud/xctool,LegNeato/xctool,1yvT0s/xctool,PSPDFKit-labs/xctool,bhamiltoncx/xctool,1yvT0s/xctool,ACChe/xctool,FiftyThree/xctool,Richardlihui/xctool,facebook/xctool,yaoxiaoyong/xctool,leopardpan/xctool,dvor/xctool,soundcloud/xctool,Richardlihui/xctool,jspahrsummers/xctool,theiren46/xctool,SuPair/xctool,theiren46/xctool,SuPair/xctool,trello/xctool,kernandreas/xctool,Monits/xctool,bgertzfield/xctool,trello/xctool,ekingo/xctool,FiftyThree/xctool,soundcloud/xctool,modulexcite/xctool,duk42111/xctool,blighli/xctool,n054/xctool,lpios/xctool,kernandreas/xctool,leopardpan/xctool,agreco/xctool,agreco/xctool,modulexcite/xctool,1yvT0s/xctool,SuPair/xctool,bhamiltoncx/xctool,FiftyThree/xctool,FiftyThree/xctool,adamjernst/xctool,facebook/xctool,lpios/xctool,adamjernst/xctool,dvor/xctool,theiren46/xctool,duk42111/xctool,Richardlihui/xctool,facebook/xctool,trello/xctool,bgertzfield/xctool