ts: refactor OpenCV tests

- removed tr1 usage (dropped in C++17)
- moved includes of vector/map/iostream/limits into ts.hpp
- require opencv_test + anonymous namespace (added compile check)
- fixed norm() usage (must be from cvtest::norm for checks) and other conflict functions
- added missing license headers

modules/imgproc/test/ocl/test_histogram.cpp

@@ -53,12 +53,11 @@
 //M*/
 
 #include "../test_precomp.hpp"
-#include "cvconfig.h"
 #include "opencv2/ts/ocl_test.hpp"
 
 #ifdef HAVE_OPENCL
 
-namespace cvtest {
+namespace opencv_test {
 namespace ocl {
 
 ///////////////////////////////////////////////////////////////////////////////
@@ -272,6 +271,6 @@ OCL_TEST_P(CalcHist, Mat)
 OCL_INSTANTIATE_TEST_CASE_P(Imgproc, CalcBackProject, Combine(Values((MatDepth)CV_8U), Values(1, 2), Bool()));
 OCL_INSTANTIATE_TEST_CASE_P(Imgproc, CalcHist, Values(true, false));
 
-} } // namespace cvtest::ocl
+} } // namespace opencv_test::ocl
 
 #endif // HAVE_OPENCL