Zombie Fortress 0.5.5 Released

A patch to 0.5.4, this update actually holds a lot of new features behind the hood which are not exactly interesting to discuss.

Changes from 0.5.4 to 0.5.5:
- Once again, a new auto-balance has been designed.
- Round timer related bugs have been fixed.
- Class help information has been updated.
- Zombie winning due to all survivors being dead no longer uses cheats to accomplish the task and instead use entity inputs, making it look more professional.