// Monster Drop Database
// Add drop item to monster
//
// Structure:
// <mobid>,<itemid>,<rate>{,<randopt_groupid>,<flag>}
//
// <mobid>  : Monster ID. See db/[pre-]re/mob_db.txt
// <itemid> : Item ID.
// <rate>   : 1 = 0.01%
//            100 = 1%
//            10000 = 100%
//            Just like rate in mob_db.txt, adjusted by battle_config.
//            To remove original drop from monster, use 0 as rate.
// Optional:
// <randopt_groupid> : If set, the dropped item will be modified by Random Option Group based on db/[pre-]re/item_randomopt_group.txt
// <flag>            : 1 - The item is protected from steal.
//                     2 - As MVP Reward
