title: mailto link not working in chrome extension popup
body: <p>This issue drove me nuts for 2 days.  I made a simple chrome extension which calls a server-side program that returns HTML that I then stuff into a div in the popup.  It was all fine, except for the simple anchor link containing a "mailto:xxx@yyy.com" href. An email message composition window would not pop up. </p>
  
  <p><b>Workaround</b>:  Add target="_blank" attribute</p>
  
  <p>I would like to know why this is necessary.</p>