Modified model's static all() method to use the create() method.

In instances where we want to inject models into a page from the server, it makes sense to use Model.all().add([...]), but the model instances were not being registered because they were using the default Backbone.Collection. 

I have modified it to use a pre-attached Model.Collection class (allowing extra customization/configuration), or automatically extending the Backbone.Collection's model() method to use Model.create().