derickbailey/backbone.marionette — pull request #91 by tgcondor (2012-05-03 04:19:59+00:00)
Title: Allow beforeRender to return a deferred object just like onRender.

Useful, for example, when used with `Backbone.Relational` to call `fetchRelated` before rendering. Snippet:
```python
beforeRender: function() {
return this.model.fetchRelated('someRelation');
}
```
Also, for this to work, `beforeRender` should be called before `serializeData`, as is done in this commit.