WIP: Entries for type

Work done by @brendanoh to fix EAK resolver with the Ember Inspector Data panel.

This is in parallel with https://github.com/emberjs/ember.js/pull/4451.

I will be working cleaning it up and finalizing it.

- [x] Code and diff cleanup
- [x] Make sure it works well with EAK and the Inspector (after merging https://github.com/stefanpenner/ember-app-kit/pull/524)
- [x] `container-debug-adapter` should return strings instead of classes
- [x] Merge https://github.com/emberjs/ember.js/pull/4451 before this
- [x] Make sure it works with Ember 1.4
- [x] Clean up commits