Bug 1020514 - Make mach colorize lines that start with REFTEST TEST-UNEXPECTED-FAIL etc. r=gps.

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extra : rebase_source : 30d85f6d46894753d925c4189b598de034014fe6
Bug 889898 - Add `mach jstestbrowser`. r=gps.

Relanding without changes, as this couldn't possibly have caused the failures
that made us back it out.

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extra : rebase_source : 93c317dccb4c4311530a44efd0a941b81c953ac9