title: save image in camera roll and get asset url
body: <p>for an app I'm developing, I use UIImagePickerController to shoot a picture and store it in camera roll:</p>
  
  <pre><code>- (void)imagePickerController:(UIImagePickerController*)picker didFinishPickingMediaWithInfo:(NSDictionary*)info {
  //... some stuff ...
  
          UIImageWriteToSavedPhotosAlbum([info objectForKey:@"UIImagePickerControllerOriginalImage"], nil, nil, nil);
  
  }
  </code></pre>
  
  <p>the image is saved, now I need to get its reference url so I try to enumerate camera roll and get the last image, but I always get the image before the one I just shot.</p>
  
  <p>Anybody has an idea how to get the reference of the just saved picture?</p>
  
  <p>Thanks,
  Max</p>