title: Uncaught typeError: Cannot read property 'isModel' of undefined
body: <p>HI im getting this error after executing my code. It says "Uncaught typeError: Cannot read property 'isModel' of undefined".Im trying to display a list using my defined model named "model.login" and a store with dummy data. </p>
  
  <pre><code>Ext.Loader.setConfig({
  enabled: true,
  paths:{
      'model' : 'app/model',
      'store' : 'app/store'
  }
  
  });
  Ext.application({
      name: 'GS',
      launch: function(){
          var myStore = null;
          Ext.require('model.login', function(){
              var login = Ext.create('model.login');
              myStore = new Ext.data.Store({
                  model: login,
                  data:[
                        {id:'09803' , issued_at: 'thisurl', instance_url:'https', signature:'token', access_token:'ser'}
                        ]
              });
          });
          this.viewport = new Ext.Panel({
              fullscreen: true,
              items:[
                     {
                         xtype: 'list',
                         itemTpl: '{id}',
                         store: myStore
                     }
                     ]
          });
      }
  
  });
  </code></pre>