title: Combobox paging toolbar doesn't respond to page size
body: <p>I'm having some problems with combobox for selecting items from database.
  Since more than 100 items are loaded, I use paging toolbar at bottom of combobox.
  Now if pages size is set to 5 or 50, the paging toolbar shows page 1 of 20 or 1 of 2 depending on pagesize, but combobox shows all 100 items, and just copy them to next page like page size is not set at all.
  I tried several thing but nothing seems to make it work.
  What's wrong?</p>
  
  <pre><code>{
      xtype: 'combobox',          
      queryMode: 'local',
      valueField: 'id',
      fieldLabel: 'Description SKU',
      name: 'id_fk',
      pageSize: 5,                
      width: 400,
      padding: 5,
      store: Ext.create('Ext.data.Store',
              {
                  fields: ['id','key item','description'],
                  autoLoad: true, 
                  pageSize: 5,                        
                  proxy:
                  {
                      type: 'ajax',
                      url: 'items/load',
                      reader:
                      {
                          type: 'json',
                          root: 'data'
                      }
                  }
              }),
      tpl: Ext.create('Ext.XTemplate',
              '&lt;tpl for="."&gt;',
                  '&lt;div class="x-boundlist-item"&gt;{key item} - {description}&lt;/div&gt;',
              '&lt;/tpl&gt;'),
  
      displayTpl: Ext.create('Ext.XTemplate',
                              '&lt;tpl for="."&gt;',
                                  '{key item} - {description}',
                              '&lt;/tpl&gt;'
                              )
  }
  </code></pre>