Merge commit '43aec5ad' into merge-2.4

Conflicts:
	cmake/OpenCVConfig.cmake
	cmake/OpenCVLegacyOptions.cmake
	modules/contrib/src/retina.cpp
	modules/gpu/doc/camera_calibration_and_3d_reconstruction.rst
	modules/gpu/doc/video.rst
	modules/gpu/src/speckle_filtering.cpp
	modules/python/src2/cv2.cv.hpp
	modules/python/test/test2.py
	samples/python/watershed.py

modules/highgui/test/test_fourcc.cpp

@@ -112,4 +112,4 @@ TEST(Highgui_dshow, fourcc_conversion)
 
         EXPECT_EQ(fourcc, (unsigned long)(unsigned)fourccFromParam);
     }
-}
+}