[RFC] JSON Patch support for Ember Data

See: http://discuss.emberjs.com/t/json-patch-support-for-ember-data/6078

@machty suggested I add the proposal on discuss to this repo.

"Extend Ember data Model prototypes to have individual 'updatable' properties. Model instances can receive patch operations in response to updating or deleting records (PUT or DELETE requests) by pushing **partial** changes into the store (DS.Store#update). Create mixins for Model, Adapter & Serializer prototypes which support using a JSON Patch [rfc6902] format in payloads sent as responses in order to apply partial updates."

[rfc6902]: http://tools.ietf.org/html/rfc6902