In bug 922912, we folded back gkmedias.dll info xul.dll, so in practice, there
is no default configuration left that exercises GKMEDIAS_SHARED_LIBRARY. And
sure enough, it's been broken for months in many different ways.
The gkmedias intermediate library is however kept for webrtc signaling tests.
The update script landed without code to apply the patch files we're
carrying against upstream. It's better to do that automatically so
there's less to remember when doing an update.
Also add a patch apparently missing from the existing set to remove
a spurious declaration for 'writeSimpleBock'.