Stop Actions will is the replacement for both the Auto Restart and Temporary flags. To define that the server should restart on stop, use the RESTART keyword. To get the same result that you would get using the temporary flag, use the REMOVE_SERVER keyword.
Additionally, there is now a DELETE_SERVER keyword. This keyword does the same thing as the REMOVE_SERVER keyword, except it deletes the directory on the server ran from.
If you would like nothing special to happen when the server stops, use the NONE keyword.
This is a change to how packets are transferred; the API has not been changed.
While the difference may be unnoticable when using unencrypted packets, because of MessagePack's compact size and better handling of byte values encrypted packets should transfer faster.
This version of SubServers.Client has the same features as the Bukkit version, minus the chest interface.
This feature may be added in the future once the documentation surrounding chest interfaces becomes more thorough.