title: Page curl on top right corner of UIView / UIViewController
body: <p>I am looking to do a partial page curl (but will settle for a full page curl) that starts in the top right corner.</p>
  
  <p>I have managed to do this successfully using:</p>
  
  <pre><code>CATransition *animation = [CATransition animation];
  [animation setDelegate:self];
  [animation setDuration:1.0];
  CAMediaTimingFunction *fun=[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
  [animation setTimingFunction:fun];
  animation.type = @"pageCurl";
  animation.subtype=@"fromRight";
  animation.fillMode = kCAFillModeForwards;
  animation.endProgress = 0.75;
  [animation setRemovedOnCompletion:NO];
  [[bckground layer] addAnimation:animation forKey:@"pageCurlAnimation"];
  </code></pre>
  
  <p>But as this uses a Private API- I can't risk being rejected when submitting my app.</p>
  
  <p>Anyone know how I can get either <code>UIViewAnimationOptionTransitionCurlUp</code> or <code>UIModalTransitionStylePartialCurl</code> working from the top right corner?</p>