title: Is there a way to get superscripts to show up in highchart exports
body: <p>I'm using the sup tag in various places on a Highcharts chart, however I noticed that the superscripts do not display at all when performing an export to any of the supported formats.</p>
  
  <p>Here's a fiddle that shows the problem:
  <a href="http://jsfiddle.net/u7gqgybj/1/" rel="nofollow">http://jsfiddle.net/u7gqgybj/1/</a></p>
  
  <p>It displays as expected when viewing the page, but when you export to say "PNG" the superscript goes away.</p>
  
  <p>The word "true" in the title should be superscript.</p>
  
  <p>In addition to I've tried a CSS approach and that also doesn't display correctly upon export</p>
  
  <pre><code>&lt;span style="vertical-align:super;font-size:0.83em;"&gt;foo&lt;/span&gt;
  </code></pre>
  
  <p>Any insight would be appreciated.</p>