Armor break change

Add a damage bonus to armor break based on the percentage of endurance lost on the damaged piece of armor.

Example:

- AB damage: 20

- Part hit: plate legs

- Current endurance: 750/1000 (25% lost)

- AB final damage: 25 (20 + 5, which is 25% of 20)

This tries to make AB scale up nicely against MA sets, which will considerably lower its damage.