title: Fabric.js - Grouped iText not editable
body: <p>The title says all. When a <code>fabric.IText</code>is part of a <code>fabric.Group</code>, it no longer reacts like a editable text.</p>
  
  <p>Here is a use-case: <a href="http://jsfiddle.net/vAjYd/" rel="noreferrer">http://jsfiddle.net/vAjYd/</a></p>
  
  <p>Is there a way to solve this problem? Otherwise I have to write my on group.</p>
  
  <p>Btw: A <code>fabric.Group</code> has many advantages, but the disabled eventing makes it impossible to use for UI-Elements (i.e. this use-case or groups of buttons as groups of texts and rects). </p>