The interface definition for a PureMVC Controller.
In PureMVC, an IController implementor
follows the 'Command and Controller' strategy, and
assumes these responsibilities:
ICommands
are intended to handle which INotifications.IObserver with
the View for each INotification
that it has an ICommand mapping for.ICommand
to handle a given INotification when notified by the View.ICommand's execute
method, passing in the INotification.ICommand previously registered as the
handler for INotifications with the given notification name.ICommand class as the handler
for a particular INotification.ICommand to INotification mapping.