title: ExtJs 4, is there a way to find control? (not by "id")
body: <p>I have button with <code>id = 'someid'</code>, i can find it by <code>Ext.getCmp('someid')</code>... </p>
  
  <p><strong>Is there a way to set some kind of "extraId" to that button, and find that button by "extraId'?</strong></p>