title: Where is the Ext JS 4 ux package
body: <p>I'm learning ExtJS 4 and I just figured out how to center containers/panels. In order to do this I needed to add the following at the top of my my app.js</p>
  
  <pre><code>Ext.Loader.setPath('Ext.ux', 'extjs/examples/ux');
  Ext.require('Ext.ux.layout.Center');
  </code></pre>
  
  <p>The ux folder is in the example folder that came with ExtJS 4, I'm wondering why this package and some others are in the examples folder rather than being in the src folder with the rest of the framework.</p>