3.0 - WIP - Added accessor method getView() to ViewVarsTrait.

Let me know if this seems worth pursing.

`AppView` allows setting defaults and then in controller you would use `$this->getView()->foo` to modify stuff as needed. `Controller::$helpers` and similar view related properties would be gone.
It allows `AppView` to be optional and not break existing apps :smile:. Though I will add it to the app skeleton so that people become aware of it.