title: Ext js FormPanel is not showing panel items when toolbar is present
body: <p>I seem to be having a weird issue here.  An extended component has the following code:</p>
  
  <pre><code>MyApp.panels.RelationshipDetails = Ext.extend(Ext.FormPanel, {
      closable: true,
      relationshipId: null,
      documentId: null,
      title: 'Relationship',
      initComponent: function () {
          if (!this.verifyRequiredData()) {
              MyApp.panels.RelationshipDetails.superclass.initComponent.call(this);
              return;
          }
  
          // Build components
          this.tbar = this.buildToolbar();
          this.items = this.buildDetailItemArray();
  
          MyApp.panels.RelationshipDetails.superclass.initComponent.call(this);
      },
  
      verifyRequiredData: function () {
          // Verification code here
      },
  
      buildDetailItemArray: function () {
          return [{
              xtype: 'fieldset',
              title: 'Details',
              collapsible: true,
              autoHeight: true,
              items: [{
                  xtype: 'hidden',
                  name: 'Id'
              }, {
                  xtype: 'textfield',
                  fieldLabel: 'Name',
                  name: 'Name'
              }, {
                  xtype: 'textfield',
                  fieldLabel: 'Description',
                  name: 'Description'
              }, {
                  xtype: 'button',
                  text: 'Save',
                  name: 'saveButton'
              }]
          }];
      },
  
      buildToolbar: function () {
          return new Ext.Toolbar({
              // Toolbar Config
          });
      }
  });
  </code></pre>
  
  <p>The issue is that when this panel renders, the toolbar is the only thing that renders.  Through debugging I can see that <code>BuildDetailItemArray()</code> is being called correctly and returning the correct result.</p>
  
  <p>It gets even weirder when I comment out the <code>this.tbar =</code> line, because when the toolbar is not present, the fieldset and field renders correctly.  This occurs even if I extend <code>Panel</code> instead of <code>FormPanel</code>.  I also tried abstracting out the form fields into it's own component, and the same thing occurs.</p>
  
  <p>Anyone have any idea why this doesn't seem to work?</p>