added gpu type selection in OPENCV_OPENCL_DEVICE parser
added 3-channels support to cv::Canny
case-insensitivity
eliminated restriction delta == 0 from cv::sepFilter2D
Merge pull request #2512 from KonstantinMatskevich:ocl_gpu_type_parser
Merge pull request #2522 from ilya-lavrenov:tapi_canny
Merge pull request #2525 from ilya-lavrenov:tapi_sep