Ensure that the allocated surface is always large enough.

git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@36332 b3059339-0415-0410-9bf9-f77b7e298cf2
vo_aa: Specifying a single option should only change the
value of that option.

Previous code mean that specifying anything at all would
disable all aalib options.

git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@36333 b3059339-0415-0410-9bf9-f77b7e298cf2
vo_gl: Make yuv=8 compatible with OpenGL in addition to OpenGL ES.

git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@36334 b3059339-0415-0410-9bf9-f77b7e298cf2