ng-admin integration

This will provide basic ng-admin integration.

ng-admin is not fully functional since I know @amitaibu has been playing with it and can replace the necessary code in `src/restful-app.js`. My ultimate goal is to configure ng-admin by making `OPTIONS` calls to the RESTful API, but one step at a time.

**Important change:** This PR will turn the RESTful Angular example module into an AngularJS app repository, and it will serve them without the Drupal theme to convey that they are separated front-end apps. See the GIF.

![angular-app-repo](https://cloud.githubusercontent.com/assets/1140906/5259775/2c308b66-7a06-11e4-9601-3a384ab808cc.gif)