mozilla-b2g/gaia — pull request #11547 by ranbena (2013-08-15 11:30:46+00:00)
Title: [BUG 905613] Remove xulrunner*.{zip,tar.bz2} before downloading it [r=21]

https://bugzilla.mozilla.org/show_bug.cgi?id=905613

Also added it to make really-clean