Removed BitmapAnimation

Signed-off-by: Grant Skinner <info@gskinner.com>
Split the extends method into extend & promote.

Renamed extends.js to core.js

Signed-off-by: Grant Skinner <info@gskinner.com>
Updated all classes to use extend/promote.

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