Merge pull request #769 from apavlenko:fix_2901
Merge pull request #771 from gpsinghsandhu:surfFeatureFinder
Merge pull request #775 from bitwangyaoyao:2.4_fixerr
Merge pull request #777 from taka-no-me:ocl_win_hang
Merge pull request #778 from asmorkalov:android_wanr_fix
Add HoughTransform examples python2

houghlines.py for HoughLinesP() and HoughLines()
houghcircles.py for HoughCircles()
remove the C3 kernels in arithm, as the oclMat will never store 3 channels data
Fix bug #2590

replaced wrong check to correct check
Merge branch '2.4'
merge add and sub into one set of kernels
Merge pull request #780 from sivapvarma:2.4
Merge pull request #779 from sivapvarma:master
ocl: Add dft based convolve implementation.

Match template in ocl module now can be utilized with dft based
convolve. Note this feature needs OpenCV to be built with clAmdFft
library.
Fix bitness detection for target platform
Fix some compilation errors and warnings.
Add some documentation on ocl::convolve
fixed compilation with CUDA
fix build without gpu module with cuda
Merge pull request #784 from jet47:fix-gpu-build
Merge pull request #786 from cuda-geek:fix-build-gpu-off-cuda-on