title: Tastypie ordering of nested relationships
body: <p>I am using a nested relationship to return grouped messages and was wondering how i can order the nested messages so that they are ordered chronologically. </p>
  
  <pre><code>class MessageGroupResource(ModelResource):
    messages = fields.ToManyField('lookup.api.MessageResource', 'message_set', full=True);
    class Meta:
      queryset = MessageGroup.objects.all();
      resource_name = 'message'
      authorization= UserAuthorization()
      ordering  = [
                   'sendTime',                    
                  ]
  
  
  
  class MessageResource(ModelResource):
    messageGroup = fields.ForeignKey(MessageGroupResource, 'messageGroup')
    class Meta:
      queryset = Message.objects.all()
      resource_name = 'submessage'
      authorization= UserAuthorization()
  </code></pre>