Support binding to events with mixed case

[sorvell]

A number of dom events have mixed case. Attributes are all lowercase so we can't match the event name directly using the attribute.

Here's a partial list with mappings:

{
  webkitanimationstart: 'webkitAnimationStart',
  webkitanimationend: 'webkitAnimationEnd',
  webkittransitionend: 'webkitTransitionEnd',
  domfocusout: 'DOMFocusOut',
  domfocusin: 'DOMFocusIn',
  dommousescroll: 'DOMMouseScroll'
}

[sjmiles]

Oops