title: How to implement "mustMatch" and "selectFirst" in jQuery UI Autocomplete?
body: <p>I recently migrated a few of my Autocomplete plugins from the one produced by <a href="http://bassistance.de/jquery-plugins/jquery-plugin-autocomplete/" rel="nofollow noreferrer">bassistance</a> to the <a href="http://jqueryui.com/demos/autocomplete/" rel="nofollow noreferrer">jQuery UI autocomplete</a>.</p>
  
  <p>How can the "mustMatch" and "selectFirst" be implemented with just callbacks and other options without modifying the core autocomplete code itself?</p>