A Base INotifier implementation.
MacroCommand, Command, Mediator and Proxy
all have a need to send Notifications.
The INotifier interface provides a common method called
sendNotification that relieves implementation code of
the necessity to actually construct Notifications.
The Notifier class, which all of the above mentioned classes
extend, provides an initialized reference to the Facade
Singleton, which is required for the convienience method
for sending Notifications, but also eases implementation as these
classes have frequent Facade interactions and usually require
access to the facade anyway.