Not all Linux systems are based on Debian, and even if they are inspired
by Debian (Buildroot), they do not necessarily use the same defaults.
This patch probes the current system for:
- dbus user and group
- dbus PID file
If the user/group cannot be found we fall back to "root", if the PID
file cannot be determined we ignore PID file readiness.
Signed-off-by: Joachim Wiberg <troglobit@gmail.com>