Huge overhaul to the system to use accounts.

This change started out small but is now much larger. It does a complete overhaul of the whole system to make everything work with accounts over hostnames. Hostnames are still used, albeit only as a fallback method if the user is not logged in. Stasis uses both account and hosts at all times. Here is what was modified (might forget some, did a lot of changes):

- Support for account for the following commands: `notice`, `simple`, `away`/`back`/`out`/`in`, `fallow`/`fdeny` and `fstasis`.
- New `ACCOUNTS_ONLY` setting, which completely ignores hostmasks (except for stasis, which is special case) and disallows unidentified players from joining the game. They can still be fjoined.
- Admin, owner, allow and deny support for accounts. Admin and owner checks for both, while allow and deny are subject to the same restrictions as the rest.
- Allow and deny dicts were moved to `botconfig` (previously `settings.wolfgame`). All references to the dicts were updated. Thanks to one of my previous commits (from Pull Request #86 ), those dicts can be set directly from the config.
- New `LEAVE_ON_LOGOUT` setting (defaulting to off), which will remove the user from the game if they log out. Added matching quit message (for now a placeholder), stasis penalty and grace period to identify back.
- All variables have their proper database to carry over between restarts.
- Many other things I might have forgotten.

Right now not fully tested. I am committing so this can be checked and commented on, and if we find bugs I'll update this.

Don't merge yet. Discuss in -dev.