Route#controllerName takes precedence over Route#routeName during render

The suggested precedence, in my opinion, should be:

1. The controller option specifically passed to the Route#render. If
   it is passed specifically during invocation, that's a no-brainer.
2. The controller specified by the Route's controllerName property. If
   the user took the time to define the property, then it makes sense
   that the expected behavior is to use that controller as the context
   for the view.
3. If found, use the controller that matches the name of the template.
4. Finally, use the controller that matches the name of the route.