title: Highcharts: How to access range values in formatter for "columnrange" type?
body: <p>I want to customize the tooltips of my Highcharts graph. The y-axis is of type "columnrange", i.e. it has an interval for the y-value:</p>
  
  <pre><code>    series: [{
          data: [
              [-0.547571175, 0.401498266],
              [-0.960011899, 0.444655955],
              [-0.660727717, 0.862639688],
              [-0.446911722, 0.660380453],
              [-0.863925256, 0.619544707],
                 .......
          ]
      }]
  </code></pre>
  
  <p>The tooltip formatter should look something like this:</p>
  
  <pre><code>    tooltip: {
          formatter: function() {
              var point = this.points[0];
              return '&lt;b&gt;'+ point.x +'&lt;/b&gt;&lt;br /&gt;Interval:'+ point.low +' - '+ point.high;
          },
          shared: true
      }
  </code></pre>
  
  <p>But <code>point.low</code> and <code>point.high</code> are not defined... How to get these low/high values?</p>
  
  <p>Here you find a sample graph: <a href="http://jsfiddle.net/dmN3N/21/" rel="nofollow">http://jsfiddle.net/dmN3N/21/</a></p>