title: How to get timestamp of UIGestureRecognizer event?
body: <p>My <code>UIView</code> (done in <code>drawRect</code>) rendering can be slow.  This causes many pinch events to be delivered (up to seconds) too late.  The effect is that my 'drawing' is still zooming in/out after I've long lifted my fingers.</p>
  
  <p>If I had the real timestamp of the pinch events, I could simply ignore them when older than e.g. 1/20 seconds.</p>
  
  <p>Is there any way to get the time?  Or is there another way of getting rid of out-dated gesture events?</p>