0.5.9
        * Configuration keys have been drastically renamed.
        * Added a contrib script for upgrading the configuration files
          to the new format: upgrade-conffile.sh
        * Upgraded the validation process, so deprecated variables trigger warnings
          and are used as default values for the right name.
        * Better control of the tar commands, when an error occured, user is warned,
          and a temp logfile is given.
        * Huge code cleanup for providing a modular implementation for several archive
          methods.
        * New archive method : mysql
          + uses mysqldump on a list of given databases.
          + facility to choose a compression format for the resulting SQL file.