added OpenCL-accelerated(?) FAST; for now the tests fail :(
make the correctness test pass
do not use the large "score" buffer; now without non-max suppression OpenCL FAST is pretty efficient
ocl: copyMakeBorder 3-channel
finished OpenCL port of ORB
fixed bug in FAST
fixed extra whitespace
Fixed getPolicy() method to make it thread-safe.
Removed workaround for Intel platform.
Merge pull request #2474 from akarsakov:fix_getpolicy
fix for unsupported doubles
added 3 vs 4 channels performance tests
Merge pull request #2480 from vpisarev:ocl_orb
Merge pull request #2482 from ilya-lavrenov:tapi_fix
Merge pull request #2483 from ilya-lavrenov:tapi_3_vs_4
Merge pull request #2481 from akarsakov:fix_hog_intel
ocl: compare with scalar
ocl: fixes
ocl: workaround for Pow accuracy test failure
ocl: compare: remove useless perf tests