Improved/Fixed: sometimes villagers were still able to turn into witches by nearby lightning strikes. The radius in which lightning strikes around villager shopkeepers get prevented was increased from 4 to 7 blocks.
Fixed (workaround): occasionally an error did pop up for some users during thunder storms due to entities reporting to be in a different world than we are expecting them to be.
Fixed: Player shops should now identify shop owners solely by name again if running on versions which don't properly support player uuids yet (below 1.7.10, I think). Untested though.
Changed: We no longer remove all already stored owner uuids when switching from a bukkit version which supported player uuids to an older versions which doesn't. The owner uuids are not used on that older bukkit version, but we still keep them for the case that we switch back to a newer version of bukkit.
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.