title: Select project children on parent select
body: <p>I am implementing a project picker for a Rally custom app and would like to select a projects children automatically when the parent is selected from the picker. I was able to get the ObjectID and Name of the objects I want to select but can't seem to get them to be selected from the picker. I attempted this using the "fireEvent" method but had no success. Here's what I have so far:</p>
  
  <pre><code>var teamPick = this.down('#filterPanel').add({
      xtype: 'rallymultiobjectpicker',
      id: 'teams',
      modelType: 'project',
      fieldLabel: 'Teams',
      listeners: {
          select: function(field, selected) {
              Ext.create('Rally.data.WsapiDataStore', {
                  autoLoad: true,
                  fetch: [ 'Name', 'ObjectID' ],
                  filters: [
                      { property: 'Parent.ObjectID', value: selected.ObjectID }
                  ],
                  model: 'Project',
                  listeners: {
                      load: function(store, data) {
                          Ext.Array.each(data, function(child) {
                              console.log(child.get('Name')); //Logs the child name
                          });
                      }
                  }
              });
          },
          scope: this
      }
  });
  </code></pre>