title: Resize firefox add-on sdk panel from user
body: <p>Is is possible firefox add-on SDK panel to be resized from user? 
  I have read the documentation here:
  <a href="https://developer.mozilla.org/en-US/Add-ons/SDK/High-Level_APIs/panel" rel="nofollow">https://developer.mozilla.org/en-US/Add-ons/SDK/High-Level_APIs/panel</a>
   but not find way how to do this. </p>