* properly handle .mount unit state tracking when two mount points are stacked one on top of another on the exact same mount point.
Features:
+
* support units generated by a generator and placed in /run/systemd/system/; the directory is
currently ignored because it is empty before the generatores are executed
* Possibly, detect whether SysV init scripts can do reloading by looking for "echo Usage:" lines
-* Add XDG_SESSION_CLASS
-
* figure out whether we should leave dbus around during shutdown
* support closing all fds via RLIMIT_NOFILE instead of /proc, in order to make chroot stuff work.