Changes

* Follow [https://developer.mozilla.org/En/Simple_Firefox_build these instructions]; the source used hereto build Firefox for desktop, although the same as Fennec'sjust so that you can build xpcshell. As an alternative, should live in you can download a "tests" zip from a separate foldercurrent build for your platform, such as ftp://ftp.mozilla.org/pub/mozilla.org/firefox/nightly/latest-mozilla-central/firefox-23.0a1.en-US.linux-i686.tests.zip -- unzip and find xpcshell.