Added item check for third classes (as partial merge from Hercules: 1caae98).
- 1:Normal, 2:Trans/Upper, 4:Baby, 8:Third, 16:Trans.Third, 32:Third Baby (see 'doc/item_db.txt' for detail)
- Changed almost all items class on 'db/re/item_db.txt'
- Updated 'sql-files/item_db_re.sql', also fixed SQL error (bugreport:7998)
Added 'item_unconditional' as group permission, default is 'false' (see 'doc/permissions.txt' for detail).