CHANGES

- Redid settings.module and even renamed it to conf.module.
    * Settings are now grouped in basic categories like "system
      settings", "module settings" and "filters".
  * Added new settings to make Drupal easier to configure and
  to make some aspects like the watchdog scale better.

- Renamed includes/settings.php to includes/conf.php.

- Added filter support to conf.module and introduced filter hooks so
  modules can implement and export new filters.  Example filters are
  an HTML filter (implemented), a profanity filter, an url converter,
  ASCII smileys to images filter and so on ...

- Reworked the check_* functions: user contributed content/input is
  only verified and filtered once in its lifespan.

NOTES

- Altough this is a large commit, no database changes are required.