Fixed: Filter sampling did not wrap around texture borders resulting in noticeable artefacts when tiled.
Changed: Removed 24 to 16-bit color downsampling when doing RGB to YUV conversion (merged changes by Cameron Zemek see here: http://code.google.com/p/hqx/).
Optimize: Removed additional 16bit matrix as now unnecessary.
Todo: Make new wrap behavior call-time optional.