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/features2d/test/test_orb.cpp

@@ -41,8 +41,7 @@
 
 #include "test_precomp.hpp"
 
-using namespace std;
-using namespace cv;
+namespace opencv_test { namespace {
 
 TEST(Features2D_ORB, _1996)
 {
@@ -123,3 +122,5 @@ TEST(Features2D_ORB, crash)
 
     ASSERT_NO_THROW(orb->compute(image, keypoints, descriptors));
 }
+
+}} // namespace