title: extjs scope of renderer
body: <p>Inside a tabpanel, there is an object like this:</p>
  
  <pre><code>tabpanel.counter = 3;
  </code></pre>
  
  <p>Inisde the tabpanel, there is a tab t. Inside t, there is a gridpanel. One of the columns in the gridpanel needs to use a renderer. In the renderer function, the record, store, cell, row , column etc are available.  </p>
  
  <p>But in the renderer function, is there a way to access the counter object defined at the tabpanel scope? What is the scope in which the renderer function runs by default? ColumnModel or GridPanel?</p>