Deprecate EmberObject Usage?

Each adapter inherits for EmberObject. Is it possible for us to just write native classes?

Start by finding the adapter classes that inherit from EmberObject and reading the old discussion before changing code. The issue does not name files, tests, or an agreed migration plan; done would mean the project has consensus on replacing EmberObject inheritance with native classes and the adapter test suite still passes.

索引モデルが issue の本文から書いたものです。