Improvements for gameplay — Precursors: Armored Angels Steam update #401987

- Game level balance in very early missions. Mainly for the easy level, this mode should be a bit more occasional than lethal at this stage of the game. - Correction for tungsten armor coating. Bonus changed from 5 to 8 to make the change more tangible to tritanium armor. Tungsten armor has improved heat dissipation, but previously had a lower coverage bonus than tritanium armor. Now it is a bit better in this aspect as well.