[gdm] Created tag 3.15.3.1

[Ray Strode <halfline src gnome org>]

The unsigned tag '3.15.3.1' was created.

Tagger: Ray Strode <rstrode redhat com>
Date: Fri Dec 19 09:11:40 2014 -0500

    Version 3.15.3.1
    
    - Actually set XDG_SESSION_TYPE in user sessions
    - Don't require plymouth if using systemd
    - require --without-plymouth to disable plymouth support

Changes since the last tag '3.15.3':

Ray Strode (8):
      Revert "session: set session type to "x11" or "wayland" as appropriate"
      session: send display made in gdm_session_open_session
      session: set session type to "x11" or "wayland" as appropriate
      Revert "configure: require plymouth if using systemd"
      configure: require --without-plymouth to disable plymouth support
      systemd: strip plymouth bits from unit file if built --without-plymouth
      NEWS: update for release
      configure: bump to 3.15.3.1