- exclude from getBuildInformation()
- fix pylint version

- FFmpeg 3.4.8

- to reduce binaries size of FFmpeg Windows wrapper
- MinGW linker doesn't support -ffunction-sections (used for FFmpeg Windows wrapper)
- move code to improve locality with its used dependencies
- move UMat::dot() to matmul.dispatch.cpp (Mat::dot() is already there)
- move UMat::inv() to lapack.cpp
- move UMat::mul() to arithm.cpp
- move UMat:eye() to matrix_operations.cpp (near setIdentity() implementation)
- move normalize(): convert_scale.cpp => norm.cpp
- move convertAndUnrollScalar(): arithm.cpp => copy.cpp
- move scalarToRawData(): array.cpp => copy.cpp
- move transpose(): matrix_operations.cpp => matrix_transform.cpp
- move flip(), rotate(): copy.cpp => matrix_transform.cpp (rotate90 uses flip and transpose)
- add 'OPENCV_CORE_EXCLUDE_C_API' CMake variable to exclude compilation of C-API functions from the core module
- matrix_wrap.cpp: add compile-time checks for CUDA/OpenGL calls
- the steps above allow to reduce FFmpeg wrapper size for ~1.5Mb (initial size of OpenCV part is about 3Mb)

backport is done to improve merge experience (less conflicts)
backport of commit: 65eb9467

* videoio(ffmpeg): eliminate MSVC build warnings

* videoio(ffmpeg): update initialization code

- repair FFmpeg logger settings on each .open() call

* 3rdparty: update libwebp 1.1.0 => 1.2.0

- https://github.com/webmproject/libwebp/releases/tag/v1.2.0

* 3rdparty(libwebp): re-apply OpenCV patches

- https://gitlab.com/libtiff/libtiff/-/tags/v4.2.0

backport of commit: 61119358
partial backport of commit: dd597616

* Add Spaghetti algorithm for CCL

* Add stat tests for new and old algorithms

* Switch license header to short version

Caused by overflow of arithmetic operators conversion rank

* improve map allocation check

* fix accoring to CR

apply partial sort to save computations

* apply partial sort

* fix typo

* fix accroding to CR

* Update py_setup_in_ubuntu.markdown

- remove duplication kind

* Fixed OCL implementation of pyrlk

If prevPts size is (N, 1) (which is a default layout for converting `vector<Point2f>` to `UMat`) the `prevPts.cols == 1` and optical flow will be calculated for the first point only.
Getting `prevPts.total()` as in line 1048 is the correct way to get points count.

* fixed compilation warning (size_t to int)
Signed-off-by: NSergey Krivohatskiy <s.krivohatskiy@gmail.com>

- follows iso c++ guideline C.44
- enables default compiler-created constructors to
  also be noexcept

original commit: 77e26a7d

- handled KernelArg, Image2D