Update Armor.h

added bonus fields and bonus computational routines:
int tuBonusAbs, _tuBonusPercent, _staminaBonusAbs, _staminaBonusPercent, _strengthBonusAbs, _strengthBonusPercent
int getTUBonus(int tu);
int getStaminaBonus(int stamina);
int getStrengthBonus(int strength);