- 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

- emulated frame counter (with autodetection of GStreamer broken behavior)
- skip 'seek' tests if seeking is not supported by backend
- update 'fps' and total frames checks (increase error tolerance)
- update synthetic image generation

general:
- all iterative tests have been replaced with parameterized tests
- old-style try..catch tests have been modified to use EXPECT_/ASSERT_ gtest macros
- added temporary files cleanup
- modified MatComparator error message formatting

imgcodecs:
- test_grfmt.cpp split to test_jpg.cpp, test_png.cpp, test_tiff.cpp, etc.

videoio:
- added public HAVE_VIDEO_INPUT, HAVE_VIDEO_OUTPUT definitions to cvconfig.h
- built-in MotionJPEG codec could not be tested on some platforms (read_write test was disabled if ffmpeg is off, encoding/decoding was handled by ffmpeg otherwise).
- image-related tests moved to imgcodecs (Videoio_Image)
- several property get/set tests have been combined into one
- added MotionJPEG test video to opencv_extra

- cmake dependencies search (WITH_MFX option)
- raw H264, H265, MPEG2 encoding and decoding
- tests for supported formats

This test does not return correct values with some software configurations.
Possible problem with ffmpeg on buildbot's linux-slave.

For several muxers and encoders GStreamer still drops the last frame.

- Accurate ASYC task handling for both GStreamer generations.
- Correct video duration request for videos.
- More accurate pipeline destruction.
- Correct color space conversion plugin for GStreamer 1.0.