title: ExtJS listening for global keystrokes with Ext.KeyMap
body: <p>To polish up an application im developing I am adding keyboard shortcuts for common tasks. I can sue <code>Ext.KeyMap</code> to do this like so...</p>
  
  <pre><code>var map = new Ext.KeyMap("my-element", {
      key: 13, // or Ext.EventObject.ENTER
      fn: myHandler,
      scope: myObject
  });
  </code></pre>
  
  <p>But I want to detect "ss" or "qq" i.e. specific double key strokes of letters. Im not sure how to do this....</p>
  
  <p>My idea is to detect the singular keystroke, add a listener to detect a following key stroke. And to handle the gap between them, set a delayed event that deletes the listener after x amount of time.</p>
  
  <p>Any improvements/suggestions/warnings??</p>