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/calib3d/src/epnp.cpp

@@ -621,4 +621,3 @@ void epnp::qr_solve(CvMat * A, CvMat * b, CvMat * X)
     pX[i] = (pb[i] - sum) / A2[i];
   }
 }
-

modules/calib3d/src/p3p.cpp

@@ -411,4 +411,3 @@ bool p3p::jacobi_4x4(double * A, double * D, double * U)
 
     return false;
 }
-

modules/calib3d/src/p3p.h

@@ -59,4 +59,3 @@ class p3p
 };
 
 #endif // P3P_H
-

modules/calib3d/src/solvepnp.cpp

@@ -348,4 +348,3 @@ void cv::solvePnPRansac(InputArray _opoints, InputArray _ipoints,
     }
     return;
 }
-