@dzucconi: Wire up saving an article

This wires it up so that you can save (POST/PUT) articles. There's some odd bootstrapping code necessary to work with HAL here that I'll comment on inline. I haven't written tests for it yet b/c I think it's something that can be extracted into halbone, but I'd rather get this up first.

![image](https://cloud.githubusercontent.com/assets/555859/4499528/c78394c6-4a83-11e4-8230-8ffde6c90a3b.png)