title: extending chart class in extjs4 mvc framework results in "config is undefined"
body: <p>I want to extend the chart class to use in a view as part of the extjs4 MVC framework. I get this error in firebug:</p>
  
  <pre><code>config is undefined 
  [Break On This Error] me.initTheme(config.theme || me.theme);
  Chart....8936564 (line 191)
  </code></pre>
  
  <p>This is the class definition:</p>
  
  <pre><code>Ext.define('CDR.chart.Daily', {
  alias: 'widget.dailychart',
  extend: 'Ext.chart.Chart',    
  initComponent: function() {
      Ext.apply(this, {
          id: 'daily',
          insetPadding: 30,
  
       ... irrelevant code cut .......
  
      });          
      this.callParent(arguments);
    }
  });
  </code></pre>
  
  <p>This is the view class the chart is added to:</p>
  
  <pre><code>Ext.define('CDR.view.trunk.View', {
  alias: 'widget.trunkview',
  extend: 'Ext.panel.Panel',    
  requires: [
      'CDR.chart.Daily'
  ],        
  initComponent: function() {
      Ext.apply(this, {
          id        : 'itemCt',
          border    : false,
          autoScroll: true,
          layout: {
              type : 'hbox',
          },            
          items: [
              Ext.create('CDR.chart.Daily'),
              {
                  id    : 'contentCt',
                  width : 500,
                  border: false
              }
          ]
      });                
      this.callParent(arguments);
    }    
  });
  </code></pre>