RFC: v2.0

[snewcomer]

This issue is to track looking into and potentially removing the Relay implementation. I was not around when this was implemented but to the best of my knowledge, when trying to set a nested property/get a nested property, the Ember proxy is recursively called with each successive key.

GIven that we can't have native property accessors on the changeset (nor Ember.get(), this has cause considerable pain, especially has Ember core has moved to allowing native ES5 descriptor variant of get. See issues below. I have not found a way around this.

#315
#281

Action steps
I would advocate for a simpler model either removing the Relay implementation and/or involving native (polyfilled) Proxy in combination with https://github.com/poteto/ember-deep-set. It is hard to know what it looks like in the end until we play with it some more.

We have a nice suite of tests to fall back on for this refactor. However, I'm not sure all the edge cases unknownProperty helps us with, so that is the one outstanding item we need to be aware of.

Some Relay PR's.
#242
https://github.com/poteto/ember-changeset/pull/194/files

Ref #301 #245 #242

I will be really busy for the next month or so, but I'll see what I can dig into. If not much traction is gained/nobody else takes up this task, be sure it will be implemented by the end of October.

[snewcomer]

Just an update so far! `2.0-beta branch created

Pt. 1 merged into 2.0-beta branch.
#322

Pt. 2 a work in progress by @dorilla!