YUI Event Utility
    DOM event utilities

3.0.0beta1
    - DOM event, custom event, and simulate event moved to separate modules.
    - Added an event for DOM event delegation.  It only fires if the target or its descendants
      match a supplied selector.
        Y.on('delegate', fn, el, 'click', 'selector' ...
      The event facade sets the following properties:
        target: the target of the event
        currentTarget: the element that the selector matched
        container: the bound element (the delegation container)
    - Added mouseenter/mouseleave events
        Y.on('mouseenter', fn, el, 'click', 'selector' ...
        Y.on('mouseleave', fn, el, 'click', 'selector' ...
    - Added Y.on('windowresize', fn), which attempts to normalize
      when the event fires across all browsers (once at the end
      of the resize rather than continuously during the resize).
    - Fixed unsubscribeAll return value.
    - Added ability to skip facade creation where performance is a concern.
    - Moved DOMReady core to yui-base.
    - Focus/blur abstraction works in Opera when the bound element is the target
    - purgeElement only reads element guids, it does not create new ones for elements without one.
    - Event.attach returns a single handle if the result from collection processing is a single item.

3.0.0pr2
    - Fixed IE notification error when no arguments are supplied.
    - Added event-simulate.
    - getListeners works when the element has no listeners defined.
    - Event.addListener removed.  Exists only in compat layer.
    - addListerer triggers 2.x event behavior.
    - Removed extra undefined parameter passed to DOM event listeners.
    - Compat layer contains Event.on.
    - Event adapter support added to Y.on
    - Added Y.on('focus', 'blur' event adaptors (support for propagation
      of these events.)
    - publish and subscribe support an object for the type, allowing for multiple
      events/subscriptions.
    - subscriber failures throw an error by default rather than log.
    - subscriber failures are not routed through Y.fail in order to
      improve the debug experience.
    - New facades created every fire()
    - before method re-added to EventTarget, which delegates to Do.before or
      subscribe.
    - EventTarget.after will delegate to Do.after if type is a function
    - Added keylistener: Y.on('key', fn, element, 'down:13,65+ctrl+shift')
    - event:ready event deprecated in favor of domready.

3.0.0pr1
    - Initial Release