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

Conflicts:
	modules/contrib/src/retina.cpp
	modules/core/include/opencv2/core/mat.hpp
	modules/core/src/algorithm.cpp
	modules/core/src/arithm.cpp
	modules/features2d/src/features2d_init.cpp
	modules/gpu/include/opencv2/gpu/gpu.hpp
	modules/gpu/perf/perf_imgproc.cpp
	modules/imgproc/src/generalized_hough.cpp
	modules/ocl/include/opencv2/ocl/ocl.hpp
	modules/video/src/tvl1flow.cpp
	modules/video/src/video_init.cpp

modules/imgproc/src/gcgraph.hpp

@@ -380,6 +380,6 @@ bool GCGraph<TWeight>::inSourceSegment( int i )
 {
     CV_Assert( i>=0 && i<(int)vtcs.size() );
     return vtcs[i].t == 0;
-};
+}
 
 #endif