The cv::superres::createOptFlow_Simple() function along with the
simple optical flow class implementation is currently commented out
in the superres module's code, so comment it out in the example as well.
This patch removes inclusion of opencv2/contrib/contrib.hpp header,
which does not exist anymore due to removal of opencv_contrib module.
The samples including this header appear to be doing so in order to
use TickMeter class; therefore, the latter is now provided by tick_meter.hpp
header file, located in samples/gpu folder.
2. Let Farneback to be the default optical flow method.
3. Fix a timing method bug for ocl path.
4. Remove useless finish operation in farneback
5. Refactor buffer usage.