Merge remote-tracking branch 'origin/2.4' into merge-2.4

Merge remote-tracking branch 'origin/2.4' into merge-2.4

Conflicts:
	modules/ocl/include/opencv2/ocl/ocl.hpp
	modules/ocl/src/arithm.cpp
	modules/ocl/src/build_warps.cpp
	modules/ocl/src/color.cpp
	modules/ocl/src/haar.cpp
	modules/ocl/src/imgproc.cpp
	modules/ocl/src/split_merge.cpp
	modules/ocl/test/test_color.cpp
	samples/cpp/3calibration.cpp
	samples/cpp/OpenEXRimages_HDR_Retina_toneMapping.cpp
	samples/cpp/OpenEXRimages_HDR_Retina_toneMapping_video.cpp
	samples/cpp/Qt_sample/main.cpp
	samples/cpp/camshiftdemo.cpp
	samples/cpp/descriptor_extractor_matcher.cpp
	samples/cpp/distrans.cpp
	samples/cpp/generic_descriptor_match.cpp
	samples/cpp/grabcut.cpp
	samples/cpp/morphology2.cpp
	samples/cpp/segment_objects.cpp
	samples/cpp/stereo_calib.cpp
	samples/cpp/tutorial_code/Histograms_Matching/compareHist_Demo.cpp
	samples/cpp/tutorial_code/core/mat_mask_operations/mat_mask_operations.cpp
	samples/cpp/tutorial_code/introduction/display_image/display_image.cpp
	samples/cpp/tutorial_code/introduction/windows_visual_studio_Opencv/Test.cpp
	samples/cpp/tutorial_code/objectDetection/objectDetection.cpp
	samples/cpp/tutorial_code/objectDetection/objectDetection2.cpp
	samples/cpp/video_dmtx.cpp