KeyboardEventStream class

Records KeyboardEvents that occur on a particular element, and provides a stream of outgoing KeyEvents with cross-browser consistent keyCode and charCode values despite the fact that a multitude of browsers that have varying keyboard default behavior.

Example usage:

KeyboardEventStream.onKeyDown(document.body).listen(
    keydownHandlerTest);

This class is very much a work in progress, and we'd love to get information on how we can make this class work with as many international keyboards as possible. Bugs welcome!