Merged with SVN #19988.

VDPAU fixes: VDPAU colour keying (again). If the colour depth is less than 24, fallback to black for the colorkey. Unfortunately, the only colours that work consistently between 24 bit and lower depths are black and white, neither of which is a sensible colour to use as a default.

Fixed some minor issues in MePo theme that I got from there:

http://www.ronfrazier.net/ronfrazier.net/mythtv/#MePoPatches