Draw Harness Guide now refers to ViewerTest commands description
via @snippet pointing to C++ source code instead of duplicating it.
"help" command now tries to beautify output of command's description.
Doxygen configuration scripts are corrected to avoid '\n' symbols in the end of the @figure alias that caused multiple warning messages.
Other Doxygen warnings in Markdown files are eliminated.
In CMake builds the format of Doxygen warnings is set to use the style recognized by Visual Studio when compiler is MSVC.
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.
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.
