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

Conflicts:
	doc/tutorials/definitions/noContent.rst
	doc/tutorials/gpu/gpu-basics-similarity/gpu-basics-similarity.rst
	doc/tutorials/introduction/android_binary_package/dev_with_OCV_on_Android.rst
	doc/tutorials/introduction/how_to_write_a_tutorial/how_to_write_a_tutorial.rst
	modules/core/include/opencv2/core/core.hpp
	modules/core/include/opencv2/core/internal.hpp
	modules/core/include/opencv2/core/version.hpp
	modules/gpu/CMakeLists.txt
	modules/highgui/perf/perf_output.cpp
	modules/highgui/test/test_video_io.cpp
	modules/ocl/include/opencv2/ocl/ocl.hpp
	modules/ocl/perf/main.cpp
	modules/ocl/src/hog.cpp
	modules/ocl/src/initialization.cpp
	modules/ocl/src/moments.cpp
	modules/ocl/src/opencl/moments.cl
	modules/ocl/test/main.cpp
	modules/ocl/test/test_moments.cpp
	modules/python/test/test.py
	modules/ts/include/opencv2/ts/ts_perf.hpp
	modules/ts/src/precomp.hpp
	modules/ts/src/ts_perf.cpp

modules/core/src/parallel.cpp

@@ -61,6 +61,17 @@
     #endif
 #endif
 
+#ifdef _OPENMP
+    #define HAVE_OPENMP
+#endif
+
+#ifdef __APPLE__
+    #define HAVE_GCD
+#endif
+
+#if defined _MSC_VER && _MSC_VER >= 1600
+    #define HAVE_CONCURRENCY
+#endif
 
 /* IMPORTANT: always use the same order of defines
    1. HAVE_TBB         - 3rdparty library, should be explicitly enabled
@@ -99,6 +110,18 @@
     #endif
 #endif
 
+#if defined HAVE_TBB && TBB_VERSION_MAJOR*100 + TBB_VERSION_MINOR >= 202
+#  define CV_PARALLEL_FRAMEWORK "tbb"
+#elif defined HAVE_CSTRIPES
+#  define CV_PARALLEL_FRAMEWORK "cstripes"
+#elif defined HAVE_OPENMP
+#  define CV_PARALLEL_FRAMEWORK "openmp"
+#elif defined HAVE_GCD
+#  define CV_PARALLEL_FRAMEWORK "gcd"
+#elif defined HAVE_CONCURRENCY
+#  define CV_PARALLEL_FRAMEWORK "ms-concurrency"
+#endif
+
 namespace cv
 {
     ParallelLoopBody::~ParallelLoopBody() {}
@@ -465,6 +488,14 @@ int cv::getNumberOfCPUs(void)
 #endif
 }
 
+const char* cv::currentParallelFramework() {
+#ifdef CV_PARALLEL_FRAMEWORK
+    return CV_PARALLEL_FRAMEWORK;
+#else
+    return NULL;
+#endif
+}
+
 CV_IMPL void cvSetNumThreads(int nt)
 {
     cv::setNumThreads(nt);