Add ability to get combined parameter in Controller

[ccampbell]

Right now when you call $this->request()->getParam('whatever') in a controller it defaults to getting the router param or the param passed into the controller from another view/subview. You would do $this->request()->getParam('whatever', Request::GET) to get a parameter from $_GET etc.

It would be nice if there was some method that combined $_GET, $_POST, and router/controller variables together into a single method so you could just access any variable name without caring about where it came from.