[gnome-control-center] (19 commits) Non-fast-forward update to branch wip/oholy/username-validity

[Ondrej Holy <oholy src gnome org>]

The branch 'wip/oholy/username-validity' 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:

  1a0b999... user-accounts: Check username validity over usermod

Commits added to the branch:

  443eb81... Updated Spanish translation (*)
  6735b85... Update Japanese translation (*)
  3ababb4... user-accounts: tweak the layout of the faces (*)
  d263ce1... user-accounts: Round all user images (*)
  12ad6a1... user-account: Remove border from user image button (*)
  02c288a... user-accounts: Generate a default avatar for new users (*)
  c0c6596... Updated Czech translation (*)
  1c5ac9a... Add GSound as a build-dependecy (*)
  945b85a... sound: Create new sound panel that uses the updated design (*)
  652dd8b... sound: Remove old panel (*)
  0799c86... sound: Rename new sound panel to replace old one (*)
  e98d0ee... sound: Update gvc to latest version (*)
  2105e27... printers: Fix compile warning (*)
  e50abfc... Update POTFILES.in (*)
  8ecdd32... color: Fix compile warning on g_clear_pointer (*)
  092f24d... printers: Remove unused variables (*)
  2b95f95... background: Fix compile warnings with g_clear_pointer (*)
  ed22dd2... 3.31.90 (*)
  741f338... user-accounts: Check username validity over usermod

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