The configgen tool is used to:
- generate the parser for the configuration file based on 
  the templates config_templ.h and config_templ.l
- generate the GUI frontend "doxywizard" for creating a configuration 
  file based on the templates doxywizard_templ.h and doxywizard_templ.cpp

If you want to add a new configuration option to doxygen,
then you should add a new entry the init() function in configgen.cpp

After that you can do a "make install" in this directory to update 
the config.l and config.h in doxygen's source directory.

-Dimitri