lwcolor: Fix non mod4 width LW48->RGB24 conversion.
lwcolor: Switch to integer version of LW48->RGB24 conversion using full bits.
lwinput: Split some simd related codes into files.
lwcolor: Add SSE4.1 version of LW48->RGB24 conversion.
lwcolor: Add SSE4.1 version of LW48->YUY2 conversion.