[gdm] (4 commits) Non-fast-forward update to branch wip/laney/systemd-user-switch

[Iain Lane <iainl src gnome org>]

The branch 'wip/laney/systemd-user-switch' was changed in a way that was not a fast-forward update.
NOTE: This may cause problems for people pulling from the branch. For more information,
please see:

 https://wiki.gnome.org/Git/Help/NonFastForward

Commits removed from the branch:

  920f591... manager: Find user's current graphical session, not session
  c5cecce... Pass the autostart directory via the environment
  3101b9f... Add systemd units
  d771ee4... Start gnome-session-systemd by default

Commits added to the branch:

  798f8fe... manager: Find user's current graphical session, not session (*)
  618a657... Pass the autostart directory via the environment (*)
  8986b73... Add systemd units (*)
  bb62e35... Start gnome-session-systemd by default

(*) This commit already existed in another branch; no separate mail sent