Support Firefox 14
Firefox 14 snuck past my release monitoring haxx in #6095 (closed) because they released 14.0.1 instead of 14.0. Le sigh. At any rate, time to begin the rebase dance and review https://developer.mozilla.org/en/Firefox_14_for_developers + http://beta.elchi3.de/doctracker/#list=fx&version=14.0.