1.9.1 beta 2 checkins

There are a lot of things queuing up to check in for the 1.9.1 beta 2 freeze. We want to make sure that there's adequate test coverage for everything, so we know what to back out when tests fail. Please sign up below for a chance to push.

Name	Description/Bug#
gavin	bug 235853 PAC bug, bug 461803 elementFromPoint changes, bug 17612 view-source link browsing front-end patch (very safe)
smontagu	bug 428317 Indic ligatures on OSX (in timezone +0200, will be online again before freeze time)
rob_strong	bug 324121 Extensions with available updates for the next version of the app should not be listed in app update extension will be disabled warning
peterv	bug 457022 Cache DOM wrappers in the DOM object
kinetik	bug 449315 Support WAV format in <audio> element
joe	bug 441563 Topcrash [@imgRequest::NotifyProxyListener(imgRequestProxy*)] at tokyomango.com
dietrich	bug 419792, bug 457473, bug 445737, bug 418643
karl	bug 449356 Refactor gfxPangoFontGroup (will affect perf on Linux), to land with bug 461087 add nsAutoRef.h
cpearce	bug 462953 Remove unimplemented media attributes/methods
campd	A set of offline patches and bug 461891 (switch to 2.2 safebrowsing servers).
dao	bug 436304
sdwilsh	bug 462964