title: Catch panning event in Highcharts
body: <p>Is it possible to catch event when user is panning on chart?</p>
  
  <p>I've Highcharts options set to:</p>
  
  <pre><code>chart: {
    panning: true,
    panKey: 'shift',
    events: {}
  }
  </code></pre>
  
  <p>In events object, <em>selection</em> is working. In the documentation, there's nothing about <em>pane</em> event. </p>
  
  <p>Is there a way to catch this event anyway?</p>