Snippets/Collapsible ChangesList options

Description
Drupal comes with a nice feature of collapsible fieldsets which helps to un-clutter setting pages (see http://drupal.org/node/321779). Here's the code adapted for MediaWiki's recent changes and watchlist options. Further enhancements could use a cookie to remember the user's preferences and settings from the last session.

MediaWiki 1.20
Try wrapping the code in

as recommended at JQuery.