1) Fixed a bug that would cause chested horses to be checked for in 1.8 even though those mobs don't exist
2) Fixed a typo in messages.yml it should auto fix your messages.yml provided you're using the misspelled version.
3) Fixed a bug that would send InGame notifications to players with the notify permission node even if notifications are turned off.
4) Fixed a bug with book detection that would throw an error in some very odd circumstances.
5) Cleaned up the /istack prot command it should now only show protections that are actually relevant to your server version.