title: can I add a context menu to a widget?
body: <p>I'm trying to add a context menu to a widget
  This is the menu:</p>
  
  <pre><code>var widgets = require("sdk/widget");
  var tabs = require("sdk/tabs");
  var contextMenu = require("sdk/context-menu");
  
  var menu = widgets.Widget({
      id: "menu",
      label: "Menu",
      contentURL: data.url("icon.png"),
      onClick: function() {
          //show a menu here
      }
  });
  </code></pre>
  
  <p>Is it possible to add a menu to this icon?<br>Or somehow when click show a context menu?</p>