Bump libav to v10_alpha2.

Misc. fixes and improvements.

Also add a patch to fix some interlaced VC-1 samples.


git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@5993 b64f7644-9d1e-0410-96f1-a4d463321fa5
decavcodec: prefer AVFrame fields over their AVCodecContext equivalent.

These fields correspond to the actual audio data in the AVFrame, and should always be set (otherwise, we must submit a bug report to libav).


git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@5994 b64f7644-9d1e-0410-96f1-a4d463321fa5