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/core/perf/perf_math.cpp

@@ -1,7 +1,7 @@
 #include "perf_precomp.hpp"
 
-using namespace std;
-using namespace cv;
+namespace opencv_test
+{
 using namespace perf;
 
 namespace {
@@ -158,3 +158,5 @@ INSTANTIATE_TEST_CASE_P(/*nothing*/ , KMeans,
 );
 
 }
+
+} // namespace