DefineMap's should come with their `.List` property property configured.

If I do:

```js
Todo = DefineMap.extend({

});
```

This should create a `Todo.List` automatically.

This will allow us to make  nice short hand for our models:

```js
Todo = DefineMap.extend({ .... });

realtimeRestModel(Todo, "/url/{id}");
```

(it will allow us to avoid specifying the `List` property)
