ADDED: NPC audio system, now the NPC's can actually hear you making noises.

ADDED: NPC Perception system, the bots can now sense your presence within a certain distance.

ADDED: NPC Stance system so not all NPC's have to be hostile anymore.

ADDED: NPC Alert system, now NPC's can be either:
>NORMAL: they will respond to noises when there is too much noise

>PARANOID: they will respond to every noise

>TERRORFIED: they will respond to every noise and have very bad accuracy

>UNINTERESTED: these NPC's will not respond to any noise.