facebook/xctool — pull request #263 by fpotter (2013-11-26 22:26:25+00:00)
Title: build commands are only successful if resultCode == 0 and they have no errors

This fixes #262.

Tested by changing a Run Script to emit strings in the form of "error:
blah" and "warning: "blah", and verified that xctool reported failure
and warnings correctly.