[mythtv] XVideo XvMC merge patch (v19)

[Daniel Kristjansson]

Get it here:
    http://www.mrl.nyu.edu/~danielk/mythtv/xv-xvmc-merge-v19.patch.bz2

This fixes a problem with commercial flagging in the last few versions,
NVP was asking for a avformatdecoder without video decoding when doing
commercial flagging.

This also restores the "getting a busy frame" warning to a VB_PLAYBACK
warning instead of a VB_IMPORTANT warning, this avoids tons of warnings
during commercial flagging. 

-- Daniel