title: ShouldAutorotate and GetSupportedInterfaceOrientations not called in Xamarin.iOS
body: <p>I made a UIViewController like</p>
  
  <pre><code>public class MyViewController : UIViewController
  {
      ...
  
      public override bool ShouldAutorotate ()
      {
          return true;
      }
  
      public override UIInterfaceOrientationMask GetSupportedInterfaceOrientations ()
      {
          return UIInterfaceOrientationMask.AllButUpsideDown;
      }
  }
  </code></pre>
  
  <p>and use it in AppDelegate.cs.</p>
  
  <pre><code>Window.RootViewController = new MyViewController();
  </code></pre>
  
  <p>When I run this code, "ShouldAutorotate" and "GetSupportedInterfaceOrientations" are called many times in view initializing phase, but after application view shown, they never called again.</p>
  
  <p>I checked that orientation setting in Info.plist is valid.
  iOS SDK Target is 7.1, Xamarin Studio Version is 5.0.1 (build 3) and Xamarin.iOS Version is 7.2.3.39.</p>
  
  <p>Any ideas? </p>