Added bubbles and cancelable to MouseEvent params.

Signed-off-by: Grant Skinner <info@gskinner.com>
Cleaned up mouseevent implementation in Stage.

Signed-off-by: Grant Skinner <info@gskinner.com>
Cleaned up EventBubbling and RollOver/MouseOver examples.

Signed-off-by: Grant Skinner <info@gskinner.com>