title: camera overlay view - just for preview?
body: <p>I've noticed that in OS 3.1 you can add an overlay view to the image picker with </p>
  
  <pre><code>cameraOverlayView
  </code></pre>
  
  <p>However, I've also noticed that adding a view via this method also displays the view for the entire time the UIImagePicker is displayed, when I only want to show it during the preview stage.</p>
  
  <p>Is there a way to make this only happen during preview? I don't want it to be there during the open shutter animation, or the screen that asks whether you want to use the image or retake.</p>