title: Using snapshotViewAfterScreenUpdates: to pass UIImage to view controller
body: <p>I'm using Swift with Xcode 6 Beta 6. I want my app to take a screenshot with snapshotViewAfterScreenUpdates: right before performing a segue to another view controller. This screenshot is then to be passed as a UIImage so that it can be used as a background.</p>
  
  <p>How do I do this?</p>