title: totalcountchange event not work with ext mvc
body: <p>I Create a store like this:</p>
  
  <pre><code>Ext.define('App.store.task.STask', {
         extend : 'Ext.data.Store',
         //more other code....
          listeners :{
              totalcountchange :function(){
                  console.info('1111');
              }
          }
      });
  </code></pre>
  
  <p>look the code,
  totalcountchange not work,and i can't find this event on extjs4 api。i tried many times,but not work.</p>