[gdm] (13 commits) Non-fast-forward update to branch wip/issue623

[Ray Strode <halfline src gnome org>]

The branch 'wip/issue623' 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:

  107766e... data: Remove deprecated StandardOutput=syslog

Commits added to the branch:

  2c0177a... meson: Fix keyutils pkg-config name (*)
  1cf8c4d... meson: Obey at -Dcustom-conf option when installing custom. (*)
  6629344... meson: Use correct rules path when getting udevdir from pkg (*)
  663612f... README: Update build instructions using meson (*)
  cbd1565... session: Leave to meson the duty of keeping the lists in sy (*)
  aaf82e9... meson: When possible use systemd dirs to check for systemd  (*)
  b01713b... meson: Don't look for non-existent journald dependency (*)
  6d83346... meson_options: Enable systemd-journal by default (*)
  a2d7dc2... meson: Print a summary of configured features (if on meson  (*)
  a798460... meson: Fix Xsession input file name (*)
  62d3617... Merge branch 'meson-fixes' into 'master' (*)
  b1074df... meson: Expose GDM XSession option to summary (*)
  7494be3... data: Remove deprecated StandardOutput=syslog

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