bootstrap: conf_init() works different as the documentation says

The includes/bootstarp.inc:conf_init()'s documentation does not match the current behaviour. It says the directories are

* Example for a ficticious site installed at
* http://www.drupal.org/test:
*
* 1. www.drupal.org.test
* 2. drupal.org.test
* 3. www.drupal.org
* 4. drupal.org
* 5. default

but it is really

1. $confdir/www.drupal.org.test
2. $confdir/drupal.org.test
3. $confdir/org.test
4. $confdir/www.drupal.org
5. $confdir/drupal.org
6. $confdir/default

If we want to clearly document the current behaviour we should give a longer path as an example:

* http://www.drupal.org/mysite/test/ the 'settings.php' is
* searched in the following directories:
*
* 1. $confdir/www.drupal.org.mysite.test
* 2. $confdir/drupal.org.mysite.test
* 3. $confdir/org.mysite.test
*
* 4. $confdir/www.drupal.org.mysite
* 5. $confdir/drupal.org.mysite
* 6. $confdir/org.mysite
*
* 7. $confdir/www.drupal.org
* 8. $confdir/drupal.org
* 9. $confdir/org
*
* 10. $confdir/default

See the attached patch for details.