The Minecraft Remote Toolkit is a nice toolkit to control your server. Although the wrapper itself is platform independent, the plugin for sending commands from the Minecraft server back to the wrapper is not. This project ports this Bukkit plugin to the Sponge platform.
/holdsrv [username]:<password> - Shutdown the server instance and hold it
/restartsrv [username]:<password> - Restart the server using the wrapper
/reschedulerestart [username]:<password> <time> - Set a new restart time
/stopwrapper [username]:<password> - Stops the wrapper isntance
/ping - Sends pong back
wrapperping.command.holdsrv
wrapperping.command.restartsrv
wrapperping.command.reschedulerestart
wrapperping.command.stopwrapper
wrapperping.command.ping
# The wrapper port of the running server instance
wrapper-port=1234