title: ExtJS's XmlReader field mapping not work
body: <p>I updated this with as you suggested  it doesnt seem to run with the updated mapping  either..doesnt seem to get this Ext.data.XmlReader's  field mapping to work. </p>
  
  <pre><code>Ext.require([
      'Ext.data.*',
      'Ext.grid.*'
  ]);
  
      Ext.onReady(function(){
      Ext.define('Book',{
          extend: 'Ext.data.Model',
          fields: [
              // set up the fields mapping into the xml doc
              // The first needs mapping, the others are very basic
              'Time', 'UserID', 'Type', 'Description','val0'
          ]
      });
  
  
          // create the Data Store
      var store = Ext.create('Ext.data.Store', {
          model: 'Book',
          autoLoad: true,
          proxy: {
              // load using HTTP
              type: 'ajax',
              url: 'audit-v2.xml',
              // the return will be XML, so lets set up a reader
              reader: {
                  type: 'xml',
                  // records will have an "Item" tag
                  //record: 'rows',
                 // idProperty: 'ASIN',
                  //totalRecords: '@total'
                   root: 'Root',
                   record: 'AuditTrail'
              }
          }
      });
  
  
      // create the grid
      var grid = Ext.create('Ext.grid.Panel', {
          store: store,
          columns: [
              {text: "Time", flex: 1, dataIndex: 'Time', sortable: true},
              {text: "UserId", width: 180, dataIndex: 'UserId', sortable: true},
              {text: "Type", width: 115, dataIndex: 'Type', sortable: true},
              {text: "Description", width: 100, dataIndex: 'Description', sortable: true}
              {text: "Value", width: 100, dataIndex: 'Value', sortable: true}
          ],
          renderTo:'example-grid',
          width: 540,
          height: 200
      });
  });
  </code></pre>
  
  <p>Here is the xml</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
    &lt;Root&gt;
      &lt;AuditTrail&gt;
        &lt;Time&gt;2012-01-10 09:27:30 (GMT-05:00)&lt;/Time&gt;
        &lt;UserID&gt;DX&lt;/UserID&gt;
        &lt;Type&gt;FY [REC]&lt;/Type&gt;
        &lt;Description&gt;Server: wamp&lt;/Description&gt;
        &lt;val0&gt;1&lt;/val0&gt;
      &lt;/AuditTrail&gt;
      &lt;AuditTrail&gt;
        &lt;Time&gt;2012-01-10 09:27:30 (GMT-05:00)&lt;/Time&gt;
        &lt;UserID&gt;DX&lt;/UserID&gt;
        &lt;Type&gt;FY [REC]&lt;/Type&gt;
        &lt;Description&gt;Server:tomcat&lt;/Description&gt;
        &lt;val0&gt;1&lt;/val0&gt;
      &lt;/AuditTrail&gt;
      &lt;AuditTrail&gt;
        &lt;Time&gt;2012-01-10 09:27:30 (GMT-05:00)&lt;/Time&gt;
        &lt;UserID&gt;DX&lt;/UserID&gt;
        &lt;Type&gt;FY [REC]&lt;/Type&gt;
        &lt;Description&gt;Server: apache&lt;/Description&gt;
        &lt;val0&gt;1&lt;/val0&gt;
      &lt;/AuditTrail&gt;
  &lt;/Root&gt;
  </code></pre>
  
  <p>It doesnt seem to be loading the xml</p>
  
  <p>Thanks</p>