dillon1000/react

Delegate Event Classes

React's top-level event delegation dispatches `AbstractEvent` objects that contain:

 - `nativeEvent`, the original browser event.
 - `data`, an object with custom normalized properties.

This diff creates a set of `DelegateEvent` classes that will replace `AbstractEvent`. The goal is two-fold:

 # Provide a cross-browser implementation that conforms to the DOM Level 3 Events API so people don't have to use `nativeEvent`.
 # Generalize the event object API so that it can be shared by `DOMEventManager`, a top-level event delegation WIP.

This simply implements the classes. I will follow-up by replacing `AbstractEvent` with them.