title: setExclusiveTouch ignored when using UISwipeGestureRecognizer
body: <p>I have two <code>UIViews</code> (custom scroll views) that respond to <code>UISwipeGestureRecognizer</code>. These two <code>UIViews</code> are <strong>subviews</strong> of the parent <code>UIView</code>. I want to <strong>allow only one</strong> of the subviews to respond to the recognizer.<br>
  In other words, only one should be allowed to be swiped at a time.</p>
  
  <p>Setting <code>setExclusiveTouch = YES</code> on the subviews AND/OR the parent view doesn't have any effect. </p>
  
  <p>How can I make sure that only 1 subview is being swiped at a time?</p>
  
  <p>Here's a picture:</p>
  
  <p><img src="https://i.stack.imgur.com/7MT5w.png" alt="enter image description here"></p>