title: How to draw a transparent UIToolbar or UINavigationBar in iOS7
body: <p>I would like an entirely transparent <code>UIToolbar</code> and/or <code>UINavigationBar</code>. I have tried the various incantations suggested for pre- and post-iOS 5 but none seem to work any more. </p>
  
  <p>How might this be accomplished in iOS 7?</p>