In case OPENCV_INCLUDE_INSTALL_PATH is absolute (i.e. starts with a "/"),
the path ends up with a double "/".

While this is mostly equivalent to a single slash, it may have a nasty
side effect when:
- OpenCV_INSTALL_PATH is empty
- OPENCV_INCLUDE_INSTALL_PATH is "/usr/include"
- the calling build script uses "-isystem" to specify the path to the
  headers of dependencies (to avoid warnings)

Specifying "-isystem /usr/include" breaks the path ordering, and GCC can
no longer find its "stdlib.h", thus CMake filters such statements.
Unfortunately it fails to do so when using "//usr/include".

- builds with CMAKE_SKIP_RPATH=ON should properly find project .so files from <build>/lib directory
- $ORIGIN doesn't work properly in cross-compilation mode

- make it configurable via OPENCV_TBB_RELEASE + OPENCV_TBB_RELEASE_MD5
- remove legacy support

Due to the explicitly declared copy constructor Vec<T, n>::Vec(Vec <T,n>&)
GCC 9 warns if there is no assignment operator, as having one typically
requires the other (rule-of-three, constructor/desctructor/assginment).

As the values are just a plain array the default assignment operator does
the right thing. Tell the compiler explicitly to default it.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>

…operator_warning

Crosscorr cleanup (opencv#14936)

* Simplify code for convolution destination type/size

For the 2d filter code, destination size equals source size, and the
crossCorr function even (re-)creates the output matrix with the given size.

The number of channels also have to match. The destination type() is the
one used to create the output matrix, so we can use its type() here.

This is a preparatory patch.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>

* Remove redundant destination size and type parameters from crossCorr

All calling sites of crossCorr already use (...,
mat, mat.size(), mat.type(), ...), so the parameters are redundant.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>

* Avoid using v_signmask universal intrinsic and mark it as deprecated

* Renamed v_find_negative to v_scan_forward

…_python

…SetRegistrator_getSubset_disaster_cleanup

Parmen ransac point set registrator get subset disaster cleanup (opencv#14828)

…_expr

…lude_path

…insertion_sort