[systemd] Notify systemd when booted up. JB#11788

Signed-off-by: Pekka Lundstrom <pekka.lundstrom@jollamobile.com>
Don't show systemd in help if not compiled in use

Signed-off-by: Pekka Lundstrom <pekka.lundstrom@jollamobile.com>
Merge pull request #10 from plundstr/master

[systemd] Notify systemd when booted up. JB#11788