title: Correct way of attaching/removing of UIGestureRecognizers
body: <p>What is the correct way of attaching and removing a UIGestureRecognizer on a view? </p>
  
  <p>I usually create and attach UIGestureReconizers in <code>-viewDidLoad</code>. Shall I use <code>removeGestureRecognizer</code> in the <code>-viewDidUnload</code>? Or are they automatically removed?</p>
  
  <p>For example is it a better way to create a UIGestureRecognizer property and initialize it in the viewController's init method and then attach/remove this gestureRecognizer property in <code>-viewDidAppear</code>/<code>-viewDidDisappear</code>?</p>
  
  <p>(Note I'm using ARC)</p>
  
  <p>Thanks.</p>