sep26 build

Fleshed out the character unlock system and implemented it for all characters.  Some stat tracking and fleshing out of the codex system.

Every character now has an unique thing that it needs to unlock, but for the most part they are actions that you will reach through normal gameplay. The only fairly specific unlocks are for Swordsman, for whom you need to perform stealth crits.

The rest should unlock through 15-30 minutes of gameplay.