Add new basic adapter and serializer.

Here's my start of the re-write. Some notes ... 

* The adapter / serializer are not hooked up as an addon because I don't know how to do it properly yet but I wanted to get my code out for you to look at.

* Get is working in the project I'm using to test / develop this. There will probably be some more changes for full CRUD but I'm working on it.

* I looked at the files that Ember CLI generated for a new addon and there are a bunch of files that we might want to pull in (including a setup for testing but I'm not sure if you want to use that configuration).

* I have a solution for reducing the number of queries for hasMany relationships since coalesceFindRequests doesn't work with DRF but I want to get this working first before I add more code on.

It would be helpful if you could show me how to wire this code properly in. If you're not sure as well, I can spend some time reading the Ember CLI docs a little more. Comments are appreciated. Feel free to wipe out or integrate this commit into another one. This is very much a work in progress and doesn't need to be preserved in the repo history.