Switched NPC type and rewrote all horde and member behaviour
Added config option for senses (enabled by default). When enabled if any hordes are within range to hear explosions, gunshots, tree's falling over/resource harvesting they will run towards the sound investigate.
Added throwable explosive support (since this NPC type does not have it). Zombies can throw grenades, beancans and C4, but only when they can't navigate to a targets position (for example if a player is on top of a rock, or standing on foundations)