Tune cmake-format configuration

• proper declaration of the mtime_add_example function in .cmake-format.py;
• override the default values of dangle_parens and max_lines_hwrap in .cmake-format.py for nicer output;
• document disabled cmake-lint errors;
• adjust local and private variable regular expressions in the cmake-lint configuration (see comments);
• reformat all CMake files again (also format config.cmake.in).