Initial Release
* Notifies systemd of successful startup (use with Type=notify):
* When only plugins with "load: POSTWORLD" (like this one) are active,
the server will be marked as "started" when the first world has been
loaded. At this point the server may still have to load further
worlds, but will already accept connections.
* When plugins with "load: POSTWORLD" (the default) are active, the
server will be marked as "started" when all plugins have been
loaded.