Core/Instances: Implemented DungeonEncounter.dbc for creating completed encounters mask to use in packets

Core/Dungeon Finder: Implemented new way of giving random dungeon rewards, linked to DungeonEncounter.dbc

sql/base/characters_database.sql

@@ -1786,6 +1786,7 @@ CREATE TABLE `instance` (
   `map` smallint(5) unsigned NOT NULL DEFAULT '0',
   `resettime` int(10) unsigned NOT NULL DEFAULT '0',
   `difficulty` tinyint(3) unsigned NOT NULL DEFAULT '0',
+  `completedEncounters` int(10) unsigned NOT NULL DEFAULT '0',
   `data` tinytext NOT NULL,
   PRIMARY KEY (`id`),
   KEY `map` (`map`),