Do something more interesting with events

[GGAlanSmithee]

For now, then EventHandler is nothing more than a generic event handler / emitter. This works fine, but we can probably do something more interesting, such as;

• directly emitting events from an entity
• listen to events based on components
• more...?

[GGAlanSmithee]

note: JS is more or less built around events, eventloops and callbacks. In the light of this, it feels a bit weird to maintain our own event solution. We should explore using / extending the language-built in event functionality, alternatively look for a third-party solution.