Bug 1093688 - [PP] ALA bug - Exception not working. r=mt
Bug 1100345 - Make Mulet appear as B2G for Marionette r=jgriffin

When running Gaia Marionette integration tests, we need to talk to Mulet
like if it was a B2G device. We define the "b2g.is_mulet" pref for this
purpose.