title: Ext.log function is empty function
body: <p>I try to use <a href="http://docs.sencha.com/ext-js/4-1/#!/api/Ext-method-log" rel="nofollow">Ext.log</a>, but <code>Ext.log</code> returns an empty function (<code>function () {}</code>)</p>
  
  <p>I use <code>./ext-4.1.1/ext-all-debug.js</code>. I thought only the production build removed logging functionality.</p>
  
  <p>What do I miss?</p>