[package] [tvheadend] fix dvb-tools dependency with right package name for Debian
[package] [tvheadend] create a default access control file
[package] [tvheadend] add systemd script for tvheadend; add systemctl handling to postinst and prerm
[filesystem] add diskmount-osmc package to base filesystems for target
[package] [mediacenter] update mediacenter package to include libmad0
[package] [niceprioritypolicy] [mediacenter] add package niceprioritypolicy to allow OSMC to control NICE value of mediacenter process, which can help on low power systems when AirPlay is playing audio. Make mediacenter package depend on this new package.