The EventDispatcher class is the base class for all classes that dispatch
* events. The EventDispatcher class implements the IEventDispatcher interface
* and is the base class for the DisplayObject class. The EventDispatcher
* class allows any object on the display list to be an event target and as
* such, to use the methods of the IEventDispatcher interface.
*
Event targets are an important part of the Flash® Player and
* Adobe® AIR® event model. The event target serves as
* the focal point for how events flow through the display list hierarchy.
* When an event such as a mouse click or a keypress occurs, Flash Player or
* the AIR application dispatches an event object into the event flow from the
* root of the display list. The event object then makes its way through the
* display list until it reaches the event target, at which point it begins
* its return trip through the display list. This round-trip journey to the
* event target is conceptually divided into three phases: the capture phase
* comprises the journey from the root to the last node before the event
* target's node, the target phase comprises only the event target node, and
* the bubbling phase comprises any subsequent nodes encountered on the return
* trip to the root of the display list.