[Update 0.1.3 patch notes] - Iron ore and smelting ingots buffs.

This patch aims to address the lack of iron ore and the resulting difficulty of crafting ingots. -Increased the amount of iron ore spawned in caves.

-Smelting costs for all ingots reduced, and the output per craft is doubled.

-All bow and arrow damage increased. -Barbed wire traps damage and durability increased.

-Slightly increased zombie hp to compensate for the ammo buffs. -Enemies will now try to break the traps after getting hit. -Fixed SCP-3139 getting stuck destroying buildings -Decreased enemy damage to structures.