title: Highcharts add legend on export
body: <p>I'm trying to add a legend on a pie when exporting the chart as PNG.
  Here is my code :  </p>
  
  <pre><code>var chart_23_106;
  $(document).ready(function () {
  chart_23_106 = new Highcharts.Chart({
      chart: { type: 'pie', renderTo: 'container_23_106', plotBackgroundColor: null, plotBorderWidth: null, plotShadow: false },
      title: { text: 'NRJ' },
      tooltip: { pointFormat: '{series.name}: &lt;b&gt;{point.percentage}%&lt;/b&gt;', percentageDecimals: 1 },
      plotOptions: {
          pie: { borderWidth: 0, shadow: false, allowPointSelect: true, cursor: 'pointer', dataLabels: { enabled: false } }
      },
      colors: ['#9F9F9F','#BE6EBE','#FFA74F','#B7B7D0','#CBE22A','#00C8C8'],
      credits: { enabled: false, text: "Source: Air Normand", href: "" },
      exporting:{ buttons: {
              printButton: {enabled:false},
              exportButton: {menuItems:null,onclick:function(){this.exportChart(null, 
                                          { chart: {reflow: false, width: 400}, 
                                            title: {text: "Répartition de la Consommation"}, 
                                            subtitle: {text: "Haute-Normandie"}, 
                                            plotOptions: {pie: {dataLabels: {enabled: true}, showInLegend: true}}, 
                                            credits: {enabled: true} }
                                      );}}
      }},
      lang: {exportButtonTitle: "Export image au format PNG"},
      series: [{
          type: 'pie',
          name: 'Proportion',
          data: [
          ['Activite 1',   684.6],
          ['Activite 2',   564.7],
          ['Activite 3',   244.4],
          ['Activite 4',   42.8],
          ]
      }]
  });
  });
  </code></pre>
  
  <p>In the function exportChart, all but the plotOptions gives the right effect. In the PNG file, the title is changed, subtitle and credits are added, but the dataLabels and the legend don't appear...<br>
  Anyone knowing why ?<br>
  Could anyone help me ?
  Thanks</p>