Iirc this was only async for database logging or name resolving. Neither of these is done anymore and async access of the Bukkit API can lead to strange problems like the CME described in the mentioned issue.
I decided to increment the minor version because this update does more than just patch issues (e.g. it changes the NameManager and adds new features like the autofill)
This is necessary so that we still store the messages with the & code internally as they would get saved back to the config file using the converted color code (section sign) which could lead to encoding issues on different operating systems. (It also fixes issues with strings that contain an and sign that isn't supposed to be a color code) Instead we load the real string and color messages via the prefix method which should get called in every instance where a message is send.
The NameManager appends a unique id for every player that has the same short name as another already existing one with a colon to the end of the clashing usernames. This is necessary so that a player can't just change their name to another user's old name and get access to all his shops.
This changes events to store the database Account instead of an OfflinePlayer and deprecates any event method that uses/returns OfflinePlayer. This is necessary as Bukkit#getOfflinePlayer(String) queries Mojang for the UUID when the user was not found in the local cache. As we already store this information (name to UUID mapping) in our database we should not have no need to rely on querying Mojang. (This might make transactions fail for shop owners that haven't played before but that shouldn't really be an issue in most cases)
This also fixes some conditions under which the STACK_TO_64 option did not get applied correctly and wrong inventory space checking for items with a max stack size of less than 64
Inspired by @Brokkonaut's fork this adds a new NOT_ENOUGH_SPACE_IN_YOUR_SHOP message to send to the shop owner when someone tries to sell to his shop. It also adds new %world, %x, %y and %z variables to display the shop's location in the message, adds a config option to make both the full-shop and out-of-stock messages respect /cstoggle and makes values in the locale.yml support ampersand color codes.