Automated testing framework for TBB

Mozilla has like 13 automated testing frameworks for Firefox. We should write a wrapper script that calls them all, and also performs some additional integration tests that we write.

https://developer.mozilla.org/en/Mozilla_automated_testing

Ideally, we'd want to get this framework to the point where it can easily be run by volunteers on their obscure/rare OS+AV software combinations, so we can crowdsource that testing rather than keep an instance of everything in house. There might be some additional cleanup we need to do for this, though. It looks like the Mozilla frameworks are not easy for end users to run: https://bugzilla.mozilla.org/show_bug.cgi?id=514067