Save game state past log-out

[john-science]

The game state should be preserved after log out on the user's side.

Every time you log in, you go back to where you were last.

I think this means we need an Enter/Exit point, with a prompt to end the game whenever you want.

[john-science]

Things that would need to be saved to save off the game state, currently:

• player position
• datetime
• how long the player has been awake (awake_min)