Support for auction house discount vouchers.

Contributed by ren.

L2J_Mobius_Classic_Interlude/dist/db_installer/sql/game/commission_items.sql

@@ -5,5 +5,6 @@ CREATE TABLE IF NOT EXISTS `commission_items` (
 	`price_per_unit` BIGINT NOT NULL,
 	`start_time` TIMESTAMP NOT NULL,
 	`duration_in_days` TINYINT NOT NULL,
+	`discount_in_percentage` TINYINT NOT NULL,
 	PRIMARY KEY (`commission_id`)
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1 COLLATE=latin1_general_ci;