Move all of the auth configuration values into a config file

Move all of the auth configuration values into a config file

* includes/auth/auth.php:
(Authentication::_setupDatabase): Create the database object in this method using the config values
* includes/auth/auth_default.php:
* includes/auth/auth_drupal.php:
* includes/auth/auth_phpbb2.php:
* includes/auth/auth_vbulletin.php:
(Authentication*::_setupDatabase): Remove the db creation from here and just call parent::
* includes/auth/config.php.new: New file