title: Render a Marionette region after model has been fetched
body: <p>I would like to use the approach described by Derick Bailey in "<strong>A Generic Problem Solution</strong>" in this <a href="https://stackoverflow.com/questions/10643474/binding-a-backbone-model-to-a-marionette-itemview-blocking-fetch">thread</a> to render a view after a model is fetched. I will report his solution here:</p>
  
  <pre><code> MyView = Backbone.View.extend({
    initialize: function(){
      this.model.on("sync", this.render, this);
    },
  
    render: function(){ ... }
  });
  
  
  myModel = new MyModel({id: someId});
  new MyView({
    model: myModel
  });
  
  myModel.fetch();
  </code></pre>
  
  <p>I have a slightly different situation: my view is inside a region layout. If I call the Marionette.Region.show() it works but the view is rendered twice. Calling Marionette.Region.attachView() the view render's function is called once but the content is not displayed in the page.</p>
  
  <p>Any idea?</p>