title: iOS 11 animated gif display in UIImageView
body: <p>I thought iOS 11 was supposed to bring, at long last, native support for animated gifs? But I tried this, and I didn't see any animation:</p>
  
  <pre><code>let im = UIImage(named:"wireframe.gif")!
  let iv = UIImageView(image:im)
  iv.animationImages = [im] // didn't help
  iv.frame.origin = CGPoint(0,100)
  iv.frame.size = im.size
  self.view.addSubview(iv)
  delay(2) {
      iv.startAnimating() // nope
  }
  </code></pre>
  
  <p>How is this supposed to work?</p>