Render search options by default on memberlist.php

Problem: The memberlist.php page has a "Find a member" link that causes the page to post back and reload entirely in order to just show the search criteria.

Solution: This postback IMO is not needed now that we're going with AJAX and other javascript accents/additions. The search options should be rendered by default in a hidden section and the link can be wired up with javascript to show/hide the search section.

This is trivial enough that it can be done in 3.1.