added half uv interpolation support
added prefetch
BGR15 support in MMX (untested) (so BGR15,16,24,32 are supported)
special unscaled height version (not much faster but it doesnt interpolate uv vertically)
git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@2317 b3059339-0415-0410-9bf9-f77b7e298cf2