title: extjs 4.2.1 - storemanager.lookup returning undefined
body: <p>I have a really simple program where I try to hook up a store to an Ext.panel.Grid.  I can't seem to get the Ext.data.StoreManager.lookup() in my Main.js call to return anything other than 'undefined.'   Ext.create('LeaveRequestGrid.store.LeaveRequestStore') seems to work (with some warnings), but I want to know what the correct way is to do this.</p>
  
  <p>LeaveRequestStore.js:</p>
  
  <pre><code>Ext.define('LeaveRequestGrid.store.LeaveRequestStore', {
      extend: 'Ext.data.Store',
      storeId: 'leaveRequestStore',
      autoLoad: true,
      fields: [
          'dateCreated',
          'startDate',
          'endDate',
          'leaveType',
          'totalHours',
          'approver',
          'status'
      ],
      data: {
          'leaveRequest' : [
              {   
                  'dateCreated': '12/01/2013' ,
                  'startDate' : '01/01/2014',
                  'endDate' : '01/02/2014' ,
                  'leaveType' : 'Paid Admin Leave' ,
                  'totalHours' : 16 ,
                  'approver' : 'John Smith' ,
                  'status' : 'Pending' 
              },
              {   
                  'dateCreated': '01/01/2014' ,
                  'startDate' : '02/01/2014',
                  'endDate' : '02/02/2014' ,
                  'leaveType' : 'Vacation' ,
                  'totalHours' : 16 ,
                  'approver' : 'John Smith' ,
                  'status' : 'Pending' 
              },
              {   
                  'dateCreated': '02/01/2013' ,
                  'startDate' : '03/01/2014',
                  'endDate' : '03/02/2014' ,
                  'leaveType' : 'Paid Time Off' ,
                  'totalHours' : 16 ,
                  'approver' : 'John Smith' ,
                  'status' : 'Pending' 
              }
          ]
      },
      proxy: {
          type: 'memory',
  
          reader: {
              type: 'json',
              root: 'leaveRequest'
          }
      }
  })
  </code></pre>
  
  <p>Main.js:</p>
  
  <pre><code>Ext.define('LeaveRequestGrid.view.Main', {
      extend: 'Ext.container.Container',
      requires:[
          'Ext.grid.Panel',
          'LeaveRequestGrid.store.LeaveRequestStore'
      ],
  
      xtype: 'app-main',
  
      layout: {
          type: 'fit'
      },
  
      items: [
          {
              xtype: 'grid',
              title: '&lt;div style="text-align:center"&gt;Leave Requests&lt;/div&gt;',
              //store: Ext.create('LeaveRequestGrid.store.LeaveRequestStore'),
              store: Ext.data.StoreManager.lookup('leaveRequestStore'),
              columns: [
                  {text: 'Date Created', dataIndex: 'dateCreated', flex: 1},
                  {text: 'Start Date', dataIndex: 'startDate', flex: 1},
                  {text: 'End Date', dataIndex: 'endDate', flex: 1},
                  {text: 'Leave Type', dataIndex: 'leaveType', flex: 1},
                  {text: 'Total Hours', dataIndex: 'totalHours', flex: 1},
                  {text: 'Approver', dataIndex: 'approver', flex: 1},
                  {text: 'Status', dataIndex: 'status', flex: 1}
              ]
          }
      ]
  });
  </code></pre>