title: what's the preferred visibility toggle for UIImage (like setHidden on UIButton)?
body: <p>I'd like to control visibility on a simple UI element. If it was a button, I'd just call setHiden on it, but UIImage has no such method.</p>
  
  <p>What's the preferred way of showing or hiding an image? Just making it a UIButton and not hooking it up to any methods seems wasteful.. is that really the right way to do it?</p>