Follow-up to 1f5161a2bd3c7934373146d8cac3c131536758ba

- Added explicit column names in the item_db query, to ensure it will
  throw a SQL error in case some are missing, rahter than silently
  failing and returning incorrect data.
- Added sql upgrade file to add the bindonequip column to the item_db2
  table for those who have it.
- As with all the item_db2 upgrade scripts, you need at least MySQL 5.0
  in order to run it. If your version is not compatible, or if the
  script fails for any reason, manual upgrade instructions are provided
  within the script.
- Special thanks to Mumbles.

Signed-off-by: Haru <haru@dotalux.com>