Controllers can be namespaced

Closes #2

myControllerNamespace/myController/myAction -> \Controller\MyControllerNamespace\MyController::actionMyAction()
myControllerNamespace/myController -> \Controller\MyControllerNamespace\MyController::actionIndex()

If the class \Controller\MyControllerNamespace\MyController does not exist, the router will route to \Controller\MyControllerNamespace::actionMyController().