* Added support for uchar4 attributes to Cycles' attribute system. * This is used for Vertex Colors now, which saves some memory (4 unsigned characters, instead of 4 floats). * GPU Texture Limit on sm_20 and sm_21 decreased from 95 to 94, because we need a new texture for the uchar4 attributes. This is no problem for sm_30 or newer. Part of my GSoC 2014.