- Modified conf_init() to use default.conf if nothing else can be found.
- Added some comments to hostname.conf to reflect the changes and
  provide more information on how to rename the file.

TODO
- The Drupal handbook should be updated once the CVS version is released.
- Should try to remove the remainder of info from hostname.conf and go for a
  completely web-based administration if possible.
- Does having all the settings in a SQL database make Drupal add more
  overhead than including a .conf file? If nobody knows for sure some tests
  should be done. If yes, concider having the admin interface generate an
  include file in addition to saving to the database.