title: Cancel Button in UIAlertController with UIAlertControllerStyle.ActionSheet
body: <p>I want to add a separated cancel button to my UIAlert.</p>
  
  <p>I know how to do it with UIActionSheet but it should also be possible with UIAlert, right?</p>
  
  <pre><code>var sheet: UIActionSheet = UIActionSheet();
      let title: String = "...";
      sheet.title  = title;
      sheet.delegate = self;
      sheet.addButtonWithTitle("Cancel");
      sheet.addButtonWithTitle("...")
      sheet.cancelButtonIndex = 0;
      sheet.showInView(self.view);
  </code></pre>
  
  <p>This will have a ... button and a cancel button which is separated.</p>
  
  <p>So does anyone know how to do this with </p>
  
  <pre><code>    var alert = UIAlertController(title: "...", message: "....", preferredStyle: UIAlertControllerStyle.ActionSheet)
  </code></pre>
  
  <p>?</p>
  
  <p>I'm new to xcode and swift so sorry if this question is dumb or anything... </p>