title: jQueryUI datepicker widget add 'onClose' function after widget initialization
body: <p>Let's say I have a #date field. At first I initialize it with some options (they are not important at the moment):</p>
  
  <pre><code>$('#date').datepicker(options);
  </code></pre>
  
  <p>Then, if I try to add <code>onClose</code> function, I would do:</p>
  
  <pre><code>$('#date').datepicker({onClose: function(dateText, inst){console.log("Hello World");}});
  </code></pre>
  
  <p>Howerver, this overrides options set before. Let's say I don't have access to these options - datepicker is initialized, options are set and now I need to add function <code>onClose</code>. How to do that? I've tried <code>.datepicker('option','onClose',function(){});</code> with no effect.</p>