Make block value depend on strength and melee skill

Quick and dirty change to blocking, making it dependent on str and melee skill. Unarmed blocks also use the unarmed combat skill. Effectively a nerf for most values of str and melee skill.
bugfixes
Merge remote-tracking branch 'Izicata/patch-5' into FrankenMod
Added phys_mult cap to avoid getting negative multiplier (could cause bad things).