title: fabricjs label on hover
body: <p>I try to add label when user hover element:</p>
  
  <pre><code>var rect = new fabric.Rect({
      originX: 'top',
      originY: 'top',
      width: 150,
      height: 120,
      fill: 'rgba(255,0,0,0.5)',
      transparentCorners: true
  });
  var text = new fabric.Text('hello world', {
      fontSize: 30,
      originX: 'top',
      originY: 'top'
  });
  
  canvas.on('mouse:over', function(e) {
      var group = new fabric.Group([ rect, text ], {
      left: e.target.left,
      top: e.target.top
  });
      canvas.add(group);
      canvas.renderAll();
  });
  
  canvas.on('mouse:out', function(e) {
      //e.target.set('fill', 'green');
      canvas.remove(group);
      canvas.renderAll();
  });
  </code></pre>
  
  <p>But when <code>mouse:out</code> fires i get:</p>
  
  <pre><code>Uncaught ReferenceError: group is not defined
      at i.&lt;anonymous&gt; (can.js:38)
      at i.r (fabric.min.js:1)
      at i._fireOverOutEvents (fabric.min.js:3)
      at i.findTarget (fabric.min.js:3)
      at i.__onMouseMove (fabric.min.js:4)
      at i._onMouseMove (fabric.min.js:4)
  </code></pre>
  
  <p>How can i make a group global with left and top of hovered element, or there is a better way to do that?</p>