[libwnck] Created tag 3.31.4.0

[Marco Trevisan <marcotrevi src gnome org>]

The signed tag '3.31.4.0' was created.

Tagger: Marco Trevisan (Treviño) <mail 3v1n0 net>
Date: 1546959833 +0000

    libwnck 3.31.4

Changes since the last tag '3.31.1':

Marco Trevisan (Treviño) (6):
      meson, libwnck: reuse dependency to generate progs
      meson, docs: use `ignore_headers` stanza
      meson, docs: pass deprecated-guards without quotes
      meson: use options name matching GNOME standards
      wnckprop: Force usage under X11 only
      Release: 3.31.4

xuzhen (1):
      Update class group icon when window icon was changed. Fixed Issue #135