Fix: Added a temporary check to skip saving of trades which involve a custom head item, which would otherwise currently cause a wipe of the complete save file due to a bug in bukkit's/spigot's item serialization.
If the trade for a written book fails players can sometimes still open and read the book if they close the shop and click the temporary fake book in their inventory fast enough. There is not much I can do about this..
Server crashes and improper shutdowns might cause living non-citizens shopkeeper entities to duplicate sometimes.
The 'always-show-nameplates' setting is no longer working on MC 1.8.
Compatibility with older bukkit versions is untested. If you encounter any problems let me know and I will look into it.
A bunch of entity types are only meant for experimental usage. They might cause all kinds of issues if used. See changelog of v1.50.
In the latest MC 1.8.x versions default minecraft trading logic has slightly changed (and by that those of shopkeepers as well): if a trade requires an item with special data (like a custom name, etc.) minecraft is now only allowing this trade, if the offered item is perfectly matching, including all special item data and attributes.
