Subview shorthands for assigning model or collection.

```javascript
    subviews: {
        user: {
            container: '[role=user]',
            constructor: UserView,
            model: 'model.user' // Will set model to model.user and automatically wait for it.
        },
    }
```

```javascript
    subviews: {
        todos: {
            container: '[role=todos]',
            constructor: TodoView,
            collection: 'model.todos' // Will set collection to model.todos and automatically wait for it.
        }
    }
```

Instad of using the more verbose prepareView