FindDoxygen: Optionally use custom config file
Allow to use pre-created configuration file located in custom doxygen-files storage directory.
Currently it is not possible to have doxygen.cfg files located in other places than CMAKE_CURRENT_BINARY_DIR
and named in custom manner,
but it is very useful for custom doxygen-cfg files to be located in dedicated storage directory and named correspondingly.
To allow this, the proposal is to have additional option CONFIG_FILE
that will allow to use custom config file located in custom directory
Topic-rename: FindDoxygen-custom-config-file
Edited by Brad King