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

samples/ocl/facedetect.cpp

@@ -259,7 +259,7 @@ void Draw(Mat& img, vector<Rect>& faces, double scale)
         resize(img, img, Size((int)(img.cols/scale), (int)(img.rows/scale)));
     }
     imshow( "result", img );
-    
+
 }
 
 
@@ -307,4 +307,4 @@ double checkRectSimilarity(Size sz, vector<Rect>& ob1, vector<Rect>& ob2)
             final_test_result = -1;
     }
     return final_test_result;
-}
+}