* Added AEGIS 'CLASS_' enum
 - Removed RC_BOSS, RC_NONBOSS, RC_NONDEMIHUMAN.
 - Added CLASS_NORMAL, CLASS_BOSS, CLASS_GUARDIAN enum.
 - Added CLASS_ALL, RC_ALL, ELE_ALL, SZ_ALL.
 - Item bonuses 'bAddDefClass' and 'bAddMdefClass' replaced by 'bAddDefMonster' and 'bAddMdefMonster'.
 - Item bonuses 'bIgnoreMdefRate' and 'bIgnoreDefRate' replaced by 'bIgnoreMdefRaceRate' and 'bIgnoreDefRaceRate'.
 - Added new item bonuses: bIgnoreDefClass, bIgnoreMdefRaceRate, bDefRatioAtkClass, bAddClass, bSubClass, bMagicAddClass, bWeaponComaClass, bHpDrainValueClass, bSpDrainValueClass, bIgnoreMdefClassRate.
 - Updated doc/item_bonus.txt
 - Updated db/re/level_penalty.txt & 'pc_level_penalty_mod' function.
 - Updated 'battle_calc_cardfix' function.
 - 'md->class_' replaced by 'md->mob_id'