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

Conflicts:
	modules/core/test/test_arithm.cpp
	modules/cuda/src/cascadeclassifier.cpp
	modules/imgproc/doc/geometric_transformations.rst
	modules/objdetect/src/hog.cpp
	modules/ocl/perf/perf_imgproc.cpp
	modules/ocl/src/gftt.cpp
	modules/ocl/src/moments.cpp

modules/core/test/test_arithm.cpp

@@ -1361,7 +1361,6 @@ TEST_P(ElemWiseTest, accuracy)
         op->op(src, dst, mask);
 
         double maxErr = op->getMaxErr(depth);
-        vector<int> pos;
         ASSERT_PRED_FORMAT2(cvtest::MatComparator(maxErr, op->context), dst0, dst) << "\nsrc[0] ~ " <<
             cvtest::MatInfo(!src.empty() ? src[0] : Mat()) << "\ntestCase #" << testIdx << "\n";
     }