Skeletons and goblins do too little damage

[NHogweed]

In vanilla game damage dealt by

• goblins = strength - enemy's armor;
• skeletons = strength + weapon - enemy's armor;

fighting skills are irrelevant. Meanwhile in damagecalculator.cpp they are treated as normal weapon-wielding NPCs with zero skills.

UPD:
One can also consider adding proper (for example, default to 100% unless explicitly defined in gothic.dat) support for setting monsters' hitchance.