title: how to activate a UISearchDisplayController with pre-set term?
body: <p>I'm using a UISearchViewController in a slightly non-conventional way.</p>
  
  <p>My UISearchBar is initially hidden.  When the user taps a button I unhide the UISearchBar and activate the UISearchViewController.  I also set the text of the searchbar, and tell the searchbar to become first responder.</p>
  
  <p>The problem is that the gray overlay created by the UISearchDisplayController remains visible.  It doesn't go away unless the text that I preset is cleared, and the user begins typing anew.  </p>
  
  <pre><code>    self.searchDisplayController.searchBar.hidden = NO;
      self.searchDisplayController.searchBar.text = @"term";
      [self.searchDisplayController.searchBar becomeFirstResponder]; // this actually appears to activate everything
      [self.searchDisplayController setActive: YES animated: YES]; // this activates but does not set the searchbar to 1st responder...
  </code></pre>
  
  <p>Why does the UISearchDisplayController continue to show it's gray overlay, and how do I clear it?</p>