[gdm] (35 commits) Non-fast-forward update to branch wip/laney/systemd-user

[Iain Lane <iainl src gnome org>]

The branch 'wip/laney/systemd-user' 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:

  a9337f5... manager: Find user's current graphical session, not session
  67e36b1... Pass the autostart directory via the environment
  a9d1e17... Don't pass --debug for now
  3c38058... manager: When falling back to looking up session by pid, lo
  1add2d7... manager: Look for a greeter session if we can't find a disp
  4ef04db... Start gnome-session-systemd
  4b009d5... Start gnome-login-wayland.target under wayland sessions
  b0fa414... Detect if we're running under systemd --user and fall back 

Commits added to the branch:

  4654042... libgdm: Don't unref a connection that's in use (*)
  ccba35d... libgdm: add weak pointer for connection object (*)
  6f8498c... libgdm: drop support for serializing multiple opens (*)
  f57e11b... libgdm: fix pointer/boolean task confusion (*)
  4317394... libgdm: don't keep manager proxy around longer than we need (*)
  85232f3... libgdm: use g_object_unref instead of g_clear_object for we (*)
  dc66c87... libgdm: get connection explicitly (*)
  a1b4916... libgdm: Drop weak refs on the GDBusConnection (*)
  ae4ace0... display-access-file: fix early free (*)
  c405151... display-access-file: drop unused function (*)
  e12757f... NEWS: update for release (*)
  354ee7e... configure: bump to 3.29.1 (*)
  b044333... data: correct typo in comment (*)
  2dc57da... utils: add new gdm-disable-wayland binary (*)
  a913eea... data: change cirrus blacklist to use gdm-disable-wayland (*)
  f7bda8d... Update Chinese (China) translation (*)
  4d2da18... libgdm: Unref the manager propagated from task (*)
  d3b1cc1... libgdm: Don't double-ref the connection got from task (*)
  1f5678c... libgdm: Don't leak connection on sync re-authentication (*)
  d92f4d9... libgdm: Use auto-pointers and cleanup code (*)
  7782778... libgdb: Try to reuse connections from the available proxies (*)
  a01fc3c... libgdm: Don't save manager address (*)
  aca3d13... libgdm: Return NULL on invalid client instances (*)
  8529e2d... Merge branch 'gdm-client-single-connection-getter' into 'ma (*)
  638c8df... Update Estonian translation (*)
  086d68f... daemon/gdm-session-record.c: open/close the utmp database (*)
  e8c9ba1... Merge branch 'fix_issue_381' into 'master' (*)
  71c4105... libgdm: use g_autoptr to manage objects lifecycle (*)
  ca814e5... Merge branch 'gdm-client-use-autoptr' into 'master' (*)
  9fb05d6... manager: Find user's current graphical session, not session
  4d0b762... Pass the autostart directory via the environment
  0e8dd82... Don't pass --debug for now
  0fa02c3... manager: When falling back to looking up session by pid, lo
  86b8a6d... manager: Look for a greeter session if we can't find a disp
  8ac3436... Start gnome-session-systemd by default

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