* Added dependency verification mechanism for cmake

- CMake install COMPONENT: "scripts"

* matlab: move to opencv_contrib

* cmake: preserve variables scope for processing modules

- use macro instead of function to avoid scope resets

When cross compiling with clang, the internal C++ headers are not found
when adding sysroot to -isystem, that is redundant anyway because it
will look for headers insider --sysroot path with same quality as it
would do with -isystem otherwise

Fixes errors like

FAILED: 3rdparty/openexr/CMakeFiles/IlmImf.dir/Iex/IexBaseExc.cpp.o
....
In file included from
TOPDIR/build/tmp/work/cortexa7t2hf-neon-vfpv4-bec-linux-musleabi/opencv/3.4.3+gitAUTOINC+b38c50b3_1f6d6f0626_bdb7bb85f3_34e4206aef_fccf7cd6a4-r0/git/3rdparty/openexr/Iex/IexBaseExc.cpp:43:
In file included from
TOPDIR/build/tmp/work/cortexa7t2hf-neon-vfpv4-bec-linux-musleabi/opencv/3.4.3+gitAUTOINC+b38c50b3_1f6d6f0626_bdb7bb85f3_34e4206aef_fccf7cd6a4-r0/git/3rdparty/openexr/Iex/IexBaseExc.h:48:
In file included from
TOPDIR/build/tmp/work/cortexa7t2hf-neon-vfpv4-bec-linux-musleabi/opencv/3.4.3+gitAUTOINC+b38c50b3_1f6d6f0626_bdb7bb85f3_34e4206aef_fccf7cd6a4-r0/recipe-sysroot/usr/lib//arm-bec-linux-musleabi/8.2.0/../../../include/c++/8.2.0/string:52:
In file included from
TOPDIR/build/tmp/work/cortexa7t2hf-neon-vfpv4-bec-linux-musleabi/opencv/3.4.3+gitAUTOINC+b38c50b3_1f6d6f0626_bdb7bb85f3_34e4206aef_fccf7cd6a4-r0/recipe-sysroot/usr/lib//arm-bec-linux-musleabi/8.2.0/../../../include/c++/8.2.0/bits/basic_string.h:6391:
In file included from
TOPDIR/build/tmp/work/cortexa7t2hf-neon-vfpv4-bec-linux-musleabi/opencv/3.4.3+gitAUTOINC+b38c50b3_1f6d6f0626_bdb7bb85f3_34e4206aef_fccf7cd6a4-r0/recipe-sysroot/usr/lib//arm-bec-linux-musleabi/8.2.0/../../../include/c++/8.2.0/ext/string_conversions.h:41:
TOPDIR/build/tmp/work/cortexa7t2hf-neon-vfpv4-bec-linux-musleabi/opencv/3.4.3+gitAUTOINC+b38c50b3_1f6d6f0626_bdb7bb85f3_34e4206aef_fccf7cd6a4-r0/recipe-sysroot/usr/lib//arm-bec-linux-musleabi/8.2.0/../../../include/c++/8.2.0/cstdlib:75:15:
fatal error: 'stdlib.h' file not found
              ^~~~~~~~~~
1 error generated.
Signed-off-by: Khem Raj <raj.khem@gmail.com>

- properly detect Android SDK support of Ant/Gradle projects
- divide processing of And/Gradle based projects

- Recommended compiler checks:
  - GCC: CV_GCC
  - Clang: CV_CLANG
- fixed problem with CMAKE_CXX_COMPILER_ID=Clang/AppleClang mess on MacOSX
  Details: cmake --help-policy CMP0025
- do not declare Clang as GCC compiler

* cmake: add ocv_get_smart_file_name() macro

* cmake: avoid adding files for unavailable dispatch modes

Documentation generation refactoring (#10621)

* Documentation build updates:

- disable documentation by default, do not add to ALL target
- combine Doxygen and Javadoc
- optimize Doxygen html

* javadoc: fix path in build directory

* cmake: fix "Documentation" status line

fixes CUDA build

CUDA implementation wants to convert std::vector<KeyPoint> <-> GpuMat.
There is no direct mapping from KeyPoint (mix of int/float fields)
into cv::Mat element type, so this conversion must be avoided.

Legacy mode is turned back for CUDA builds.