Fix an incorrect type cast.
Move C API of opencv_video to separate file
Move C API of opencv_calib3d to separate file
Change ocl::Canny test case category
Test code clean up.
Format ocl::Canny header
Fix a bug of ocl::Canny when src/dst using the same buffer.
Remove unused kernels.
Fix a potential bug of ocl::CannyBuf.

The program would crash if release is called twice.
Remove my test codes.
Merge pull request #798 from pengx17:master_ocl_mleak
Merge pull request #805 from pengx17:master_canny_fix
Move C API of opencv_objdetect to separate file

Also move cv::linemod to own header
Remove ifdef __cplusplus from nonfree headers
Add missed constants for reduce operation
Remove C API from OpenCL module
Merge pull request #803 from taka-no-me:split_c_cpp3