title: Rally SDK 2 manually filter or specify rallycardboard columns displayed
body: <p>I am trying to create a simple rallycardboard app that displays projects as columns with the project backlog stories as cards. Then allow the drag/drop of cards to set the project. Code is attached. </p>
  
  <p>If I specify 'Project" as the attribute, the board contains columns for all projects in the workspace. I wish to limit the columns shown to either</p>
  
  <ol>
  <li>Scoped parent and children, or </li>
  <li><p>Code a list of project columns. I have tried the manipulate the columns, columnConfig, context settings, but nothing produces the desired results. </p>
  
  <pre><code>&lt;!DOCTYPE html&gt;
  &lt;html&gt;
  &lt;head&gt;
      &lt;title&gt;CardBoard Example&lt;/title&gt;
  
      &lt;script type="text/javascript" src="/apps/2.0rc2/sdk.js"&gt;&lt;/script&gt;
  
      &lt;script type="text/javascript"&gt;
          Rally.onReady(function() {
              Ext.define('ProjBoard', {
                  extend: 'Rally.app.App',
  
                  launch: function() {
                      if (cardBoardConfig) {
                          cardBoardConfig.destroy();
                      }
  
                      var cardBoardConfig = {
                          xtype: 'rallycardboard',
                          types: ['User Story'],
                          attribute: 'Project',
                          fieldToDisplay: 'Project',
                          cardConfig: {
                              fields: ['Project', 'Parent','Iteration']
                          },
                          storeConfig: {
                              filters: [
                                  { property: 'ScheduleState', operator: '&lt;', value: 'In-Progress' },
                                  { property: 'Iteration', operator: '=', value: '' }
                              ],
                              sorters: [
                                  { property: 'Rank', direction: 'DESC' }
                              ],
                              //Specify current project and scoping
                              context: this.getContext().getDataContext()
                          }
                      };
  
                      this.add(cardBoardConfig);
                  }
              });
              Rally.launchApp('ProjBoard', {
                name: 'Backlog Project Board'
              });
          });
      &lt;/script&gt;
      &lt;style type="text/css"&gt;
      &lt;/style&gt;
  &lt;/head&gt;
  &lt;body&gt;&lt;/body&gt;
  &lt;/html&gt;
  </code></pre></li>
  </ol>