[Arp] Event implementation clarification

[Aral Balkan]

Hi Chris,

>If I have correctly understand the way the EventDispatcher class
>works, the EventDispatcher is the parent of these children. 
>
The EventDispatcher is a Mixin. Basically, a fancy way of saying that 
we're going to be extending the prototype (ie., adding methods to a 
class at runtime). Thus, the methods that get mixed in become methods of 
the class (in this case, the forms.) The difference between this and 
having a centralized EventDispatcher is that the event target will be 
the EventDispatcher, not the form that dispatched the event.

All the best,
Aral