[gnome-desktop] Created tag 3.21.4

[Frederic Peters <fpeters src gnome org>]

The unsigned tag '3.21.4' was created.

Tagger: Frédéric Péters <fpeters 0d be>
Date: Fri Jul 22 15:19:50 2016 +0200

    release: 3.21.4

Changes since the last tag '3.21.3':

Bastien Nocera (5):
      pnp-ids: Use udev's hwdb to query PNP IDs
      build: Remove dependencies on xrandr and xext
      pnp-ids: Add --disable-udev command-line argument
      wallclock: Build the test application
      bg-slide-show: Fix annotation

Frédéric Péters (1):
      3.21.4

Piotr Drąg (1):
      Add Language headers to po files