Implement pickling for GameState

[smallnamespace]

Last time I tried, pickle errored out when trying to serialize a GameState.

Pickling is necessary if anyone wants to ship a state over the wire, etc., and might also be the fastest route to writing a fast __deepcopy__

[jleclanche]

More generally I'd like to support a more streamlined gamestate (eg. tag-oriented or some such). Less magic attributes.

[smallnamespace]

So you'd like it to look more like an entity?

[cdennison]

What's the current status on this? It looks there's already a game state to entity function under utils. Is this lacking in some way?

[jleclanche]

@cdennison I have a plan I've been trying to discuss with a couple of people who are interested working on it. If you're interested as well, hop in #hearthsim and ping me!