v0.5.0

• Changed library name to BackboneFire. It is now available as backbonefire on Bower.
• Added autoSync property for one-time syncing of Backbone.Firebase.Model and Backbone.Firebase.Collection.
• Added support for url property to create a Firebase reference for Backbone.Firebase.Model and Bacbone.Firebase.Collection.
• Added a Firebase reference for each Model in a Backbone.Firebase.Collection.
• Removed firebase property from Backbone.Firebase.Model and Bacbone.Firebase.Collection.
• Removed Backbone.Firebase() constructor for syncing a Backbone.Model and Backbone.Collection.
• The sync event for a Backbone.Firebase.Collection is called on value changes.
• Models are properly prepared when adding to a Backbone.Firebase.Collection.
• Models are properly destroyed when calling Backbone.Firebase.Model.destroy().