ember-cli addon

I am publishing the PR so there could be more eyes on it. It is not ready to merge.

- [ ] cleanup generated files
- [ ] complete the README with new instructions
- [ ] make sure I did not make some stuff worse in the process of refactoring :)
- [ ] add some basic tests

Mainly I would like some feedback on how I manage configuration. Is it too much magic?
seems bad to "hardcode" the store in the adapter. I think we need an api on store to configure sync. If you look at how they are doing it in `EmberFire`, it is a pile of monkey patches... Any thought on this @igorT ?