build-sys: drop special name hack for dbus.service since a native service file is now shipped upstream dbus

main: make it possible to run a system daemon along side an aloready running one for testing purposes

units: connect shutdown scripts explicitly with the tty, because native units now default to /dev/null stdout otherwise

Fix some minor grammar and punctuation typos.

Fix minor typographic, punctuation and grammar errors.

Rename --start to --realize, to make things less confusing when doing
"systemctl stop --realize foo.service".

Introduce --realize=reload.

Don't talk to systemd when run within a chroot, or when systemd isn't
running.

systemctl: short cut things if we aren't root and the user requested a reboot to suppress unnecessary wall message

execute: if the main process of a service already owns the TTY, don't wait for acquiring it again in the reload/stop step