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/cudaarithm/test/test_buffer_pool.cpp

@@ -48,9 +48,7 @@
 #include "opencv2/core/private.cuda.hpp"
 #include "opencv2/ts/cuda_test.hpp"
 
-using namespace testing;
-using namespace cv;
-using namespace cv::cuda;
+namespace opencv_test { namespace {
 
 struct BufferPoolTest : TestWithParam<DeviceInfo>
 {
@@ -116,4 +114,5 @@ CUDA_TEST_P(BufferPoolTest, From2Streams)
 
 INSTANTIATE_TEST_CASE_P(CUDA_Stream, BufferPoolTest, ALL_DEVICES);
 
+}} // namespace
 #endif // HAVE_CUDA