title: iOS8 Cannot hide cancel button on search bar in UISearchController
body: <p>My goal is to prevent the cancel button from appearing in a search bar in a UISearchController. I started with <a href="https://developer.apple.com/library/ios/samplecode/TableSearch_UISearchController">Apple's Table Search with UISearchController sample code</a> and hid the cancel button as seen in the code snip below. However, when the user taps in the text field, the cancel button still appears. Any help?</p>
  
  <pre><code>override func viewDidLoad() {
      super.viewDidLoad()
  
      resultsTableController = ResultsTableController()
  
      searchController = UISearchController(searchResultsController: resultsTableController)
      searchController.searchResultsUpdater = self
      searchController.searchBar.sizeToFit()
      tableView.tableHeaderView = searchController.searchBar
  
      searchController.searchBar.delegate = self
  
      //Hide cancel button - added by me
      searchController.searchBar.showsCancelButton = false
  
      ...
  </code></pre>