- WITH_MKL option is enabled
- user doesn't specify MKLROOT/MKL_ROOT_DIR variables

- cmake dependencies search (WITH_MFX option)
- raw H264, H265, MPEG2 encoding and decoding
- tests for supported formats

compute() for BP and CSBP output 32-bit floating-point mat, and in cv::imshow() 32-bit floating-point is recognized as [0,1] and maped to [0,255], that causes gray window for BP and CSBP.

 - check if compiler is Intel compiler
 - remove not referenced variables

added v_reduce_sum4() universal intrinsic; corrected number of threads in cv::getNumThreads() in the case of GCD