Organize code for extensibility?

Sorry for not suggesting this before doing some work on it. I now remember that being a point brought up on the "Contributing to OSS" workshop at Nodeconf! Don't worry, the branch I made is purely a proof of concept, I wouldn't merge it until it had feature parity AND general team support.

I was thinking some of the requested features, especially adding new persisting methods, and even some ideas about adding more nuanced key state representation, would benefit from some clearer project organization.

I took a swing at this, on this branch based on this general idea:

It still has a way to go, some features are still broken, but I'm curious what others think about adding more organization/structure to the code base.

That image is not 100% accurate to that branch I'm writing. The event receiving is now handled by the Player, since the listeners are on the window object, not on the individual keys. I had that part backwards when I drew it up.

Start by reading the current Player and key event-handling code, then compare it with the proof-of-concept branch linked in the issue. Check which requested persisting methods and key-state ideas remain broken or incomplete. Done requires an agreed structure with feature parity and general team support.