[gtk] (12 commits) Non-fast-forward update to branch matthiasc/a11y

[Matthias Clasen <matthiasc src gnome org>]

The branch 'matthiasc/a11y' 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:

  2b183b6... atspi utils: Fix an oversight
  6604866... Don't pass NULL to g_variant_new_string
  20c419d... Add a GetInterfaces method
  28d96b8... Move atspi enums to gtkatspiprivate.h
  3d8ff79... atspi: Add the AtspiRelationType enum
  bee31a0... atspiroot: Stub out GetRelationSet
  184ac7e... atspicontext: Implement GetRelationSet
  66d7174... atcontext: labelled-by has a reference list
  7143544... atspicontext: Fix GetIndexInParent for toplevels
  af3b86e... wip: Begin implementing Text for labels

Commits added to the branch:

  c5d9694... Fixup: Add a forgotten #pragma once
  2c812d5... atspi utils: Fix an oversight
  2f33ef6... Don't pass NULL to g_variant_new_string
  8173fb7... Add a GetInterfaces method
  1f01546... Move atspi enums to gtkatspiprivate.h
  5152bea... atspi: Add the AtspiRelationType enum
  b13d366... atspiroot: Stub out GetRelationSet
  450e51f... atspicontext: Implement GetRelationSet
  77935f7... atcontext: labelled-by has a reference list
  b027d77... atspicontext: Fix GetIndexInParent for toplevels
  5382717... atspi: Add pango utilities
  021e8e4... atspi: Implement Text interface for labels