[gdm] (8 commits) Non-fast-forward update to branch wip/wayland-take-2

[Jasper St. Pierre <jstpierre src gnome org>]

The branch 'wip/wayland-take-2' 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:

  2bc6ced... session: Introduce the concept of the "display server mode"
  7556e6c... manager: Don't reuse the same X server when we have a displ
  f592201... session-worker: Implement support for the different display
  20c1114... Add wayland-sessions
  129a76d... session: Add a simple and naive way to detect Wayland sessi
  c16d3c9... session: Wayland sessions bypass Xsession
  ee09212... session: Wayland sessions are vt-unaware
  3c0ca1a... session: Reset immediately on cancel

Commits added to the branch:

  8aa3240... session: Introduce the concept of the "session display mode
  504652b... manager: Don't reuse the same X server for alternate displa
  0deb786... session-worker: Implement support for the different display
  9206697... Add wayland-sessions
  6178034... session: Add a simple and naive way to detect Wayland sessi
  68279c6... session: Wayland sessions bypass Xsession
  ccc45bb... session: Wayland sessions are allocated on a new VT
  b287670... session: Reset immediately on cancel