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/core/src/lapack.cpp

@@ -1823,4 +1823,4 @@ cvSVBkSb( const CvArr* warr, const CvArr* uarr,
 
     cv::SVD::backSubst(w, u, v, rhs, dst);
     CV_Assert( dst.data == dst0.data );
-}
+}