To reduce number of unnecessary rebuilds on updates of OpenCL kernels

  * guard correctly in header file
  * guard correctly in cmake file

* Adding CMake script to check if pylint is installed
* Adding Pylint config file (to choose the tests that are enabled)
* Adding CMake script to samples/python/tutorial_code

Testing: bad-indentation, mixed-indentation, unnecessary-semicolon, unused-variable

CUDA9 build fixed, added detection (#9418)

* CUDA9 build fixed, added detection

* Replacing deprecated __shfl_xxx with __shfl_sync, fixing bogus CUDA9 warnings

- Optimizations set change. Now IPP integrations will provide code for SSE42, AVX2 and AVX512 (SKX) CPUs only. For HW below SSE42 IPP code is disabled.
- Performance regressions fixes for IPP code paths;
- cv::boxFilter integration improvement;
- cv::filter2D integration improvement;

- '-fvisibility' flag was updated
- PVAPI library detection was changed

misplaced else

This is VS2017 Preview. It makes sure the version is detected properly and the INSTALL target then correctly installs to x64/vc15 (the same as MSVC1910).

Remove unnecessary Non-ASCII characters from source code (#9075)

* Remove unnecessary Non-ASCII characters from source code

Remove unnecessary Non-ASCII characters and replace them with ASCII
characters

* Remove dashes in the @param statement

Remove dashes and place single space in the @param statement to keep
coding style

* misc: more fixes for non-ASCII symbols

* misc: fix non-ASCII symbol in CMake file

- 1: OPT is available directly or via dispatcher
- 0: optimization is not compiled at all