fixed ocl::cvtColor for CV_YUV2BGRA and CV_YUV2RGBA
added YCrCb to RGB, BGR, RGBA, BGRA modes to ocl::cvtColor
color.cpp refactoring: created generic interface for toRGB and fromRGB callers
added RGB -> XYZ conversion to ocl::cvtColor
added XYZ to RGB conversion to ocl::cvtColor
added RGB[A] <-> BGR[A] conversion to ocl::cvtColor
added RGB5x5 <-> RGB conversion
added RGB5x5 <-> Gray
Merge pull request #1775 from ilya-lavrenov:ocl_cvtColor