Refactor CMake files to hide redundant variables using mark_as_advanced.
The result - no re-find will be performed.
From 30s to 5s for second time reconfiguration stage.
Documentation is generated automatically during build/install process
Added check of minimum Doxygen version.
Install process causes generation of Overview documentation (unless already generated) by checking of occt_logo.png file existing.
Overview project regenerates documentation if any source file was changed.
APPLY_OCCT_PATCH_DIR renamed with BUILD_PATCH
OCCT_ALGO_EXTENDED_OUTPUT renamed with BUILD_WITH_DEBUG
REBUILD_PLATFORM_DEPENDENT_CODE renamed with BUILD_YACCLEX
3RDPARTY_DOXYGEN_DOT_EXECUTABLE renamed with 3RDPARTY_DOT_EXECUTABLE
Generation of OCCT overview documentation added as building of "Overview" project.
BUILD_OCCT_OVERVIEW variable introduced to offer generation OCCT overview documentation in html format.
Overview md files added to overview OCCT project.
"Building with CMake" article updated; overview.html copy into an install directory.
CMAKE_BUILD_TYPE for single-configuration generators described; BUILD_CONFIGURATION removed.
