WIP: Quick post: Add RESTful backend

#143 
Restful API:

``api/blog_posts``

![selection_006](https://cloud.githubusercontent.com/assets/7369740/4789414/f1544d14-5dc4-11e4-9362-b49602828350.png)


@amitaibu PR is ready.
instead of this use:

```php
    // Single entity reference field with "resource".
    $public_fields['entity_reference_single_resource'] = array(
      'property' => 'entity_reference_single',
      'resource' => array(
        'group' => 'groups'
      ),
    );
```