Durability penalty tweak

This is a small tweak to the durability system. Only for deathmatch difficulty.

Gears will lose 10% stat at every -10% durability, capped at 40%

Weapon health at 80% - 40% lose 10% - 50% dps

Armor health at 90% - 40% will lose 10% - 60% protection

Vanilla deathmatch for reference:

-  75% durability = -10% stat reduction

- 50% durability = -20% stat reduction

Tested on 4. 03