title: reverse animation of Image Sequence?
body: <p>I have a button and I would like to give it some animation. Everything works fine, but I am trying to figure out a way to reverse the animation's image sequence order so that the button would seem to restore it's previous state. I can't find anything in the docs, and it seems like it may not be possible to reverse the image sequence? 
  If it's not possible to reverse the order, how can I give the button a different image sequence? should I reefed it with a new array?</p>
  
  <p>da code:</p>
  
  <pre><code> animatedButton = [[UIImageView alloc] initWithFrame:animButtonRect];
  [animatedButton setImage:[UIImage imageNamed:@"messaging_00014.png"]];
  [animatedButton setUserInteractionEnabled:YES];
  
  animatedButton.animationImages = [NSArray arrayWithObjects:
                              [UIImage imageNamed:@"mov_00000.png"],
                              [UIImage imageNamed:@"mov_00001.png"],
                              [UIImage imageNamed:@"mov_00002.png"],
                              [UIImage imageNamed:@"mov_00003.png"],
                              [UIImage imageNamed:@"mov_00004.png"],
                              [UIImage imageNamed:@"mov_00005.png"],
                              [UIImage imageNamed:@"mov_00006.png"],
                              [UIImage imageNamed:@"mov_00007.png"],
                              [UIImage imageNamed:@"mov_00008.png"],
                              [UIImage imageNamed:@"mov_00009.png"],
                              [UIImage imageNamed:@"mov_00010.png"],
                              [UIImage imageNamed:@"mov_00011.png"],
                              [UIImage imageNamed:@"mov_00012.png"],
                              [UIImage imageNamed:@"mov_00013.png"],
                              [UIImage imageNamed:@"mov_00014.png"],
   nil];
  
   animatedButton.animationDuration = 1.0;
   animatedButton.animationRepeatCount = 1;
  [self.view addSubview:animatedButton];
  </code></pre>