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

Conflicts:
	CMakeLists.txt
	modules/calib3d/src/calibration.cpp
	modules/ocl/src/cl_programcache.cpp
	modules/ocl/src/filtering.cpp
	modules/ocl/src/imgproc.cpp
	samples/ocl/adaptive_bilateral_filter.cpp
	samples/ocl/bgfg_segm.cpp
	samples/ocl/clahe.cpp
	samples/ocl/facedetect.cpp
	samples/ocl/pyrlk_optical_flow.cpp
	samples/ocl/squares.cpp
	samples/ocl/surf_matcher.cpp
	samples/ocl/tvl1_optical_flow.cpp

samples/gpu/super_resolution.cpp

@@ -222,7 +222,11 @@ int main(int argc, const char* argv[])
 
         if(useOcl)
         {
-            MEASURE_TIME(superRes->nextFrame(result_));
+            MEASURE_TIME(
+            {
+                superRes->nextFrame(result_);
+                ocl::finish();
+            });
         }
         else
 #endif