static function qualifier replaced on inline to enable kernel compilation with OpenCL 1.1 embedded profile.

ts dependency from CUDA runtime removed. All implicit CUDA calls replaced by calls from core module.

Improve ocl cvt_color performance for the following conversions: RGB<->BGR, RGB->Gray, RGB<->XYZ, RGB<->YCrCb, RGB<->YUV, and mRGBA<->RGBA.
The improvement was done basically by processing more than 1 pixel by each work-item and using vector's operations.
new performance tests were added