Generic state update handlers?

[tmedwards]

Currently, there's no way to update the game state if the game and state versions desynchronize in-play. For example, if the game is network-hosted and is updated with state breaking changes during someone's play session.

Between-play updates, via saves, are handled via Config.saves.version and Save.onLoad handlers.

Moving the Save machinery to State, as a more generic mechanism that can handle in-play updates too, seems like a good idea.

That said. There's probably no real need for a State equivalent to Save.onSave handlers, so that's a conundrum.