We currently have out own event system, and the DOM has one too. We should use the DOM's event system so we're more aligned with standards, and also provide a fallback implementation when running LUME in a non-DOM environment.

Should be final since it will not be inherited

Originally posted by @litelawliet in adriengivry/Overload#126 (comment)

We should do a pass to ensure classes that should be final to have the final keyword