implement required options in init.d script

Fixes the following Lintian tags:
E: mintsystem: init.d-script-does-not-implement-required-option etc/init.d/mintsystem start
E: mintsystem: init.d-script-does-not-implement-required-option etc/init.d/mintsystem stop
E: mintsystem: init.d-script-does-not-implement-required-option etc/init.d/mintsystem restart
E: mintsystem: init.d-script-does-not-implement-required-option etc/init.d/mintsystem force-reload
W: mintsystem: init.d-script-does-not-source-init-functions etc/init.d/mintsystem