[gimp] (6 commits) Non-fast-forward update to branch wip/nielsdg/vapi

[Niels De Graef <nielsdg src gnome org>]

The branch 'wip/nielsdg/vapi' 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:

  aed1a1e... libgimpwidgets: UnitStore: Fix conflicting names
  312ba47... Add support for building Vala plug-ins

Commits added to the branch:

  aa6079f... scrolledpreview: Add missing gir annotations (*)
  4f46c92... gimpintstore: Mark iter (out) annotations (*)
  69c5fd0... GimpHelpFunc: don't annotate (closure) (*)
  f5fbc3b... libgimpwidgets: UnitStore: Fix conflicting names
  2f844ef... Split GIR into Gimp-3.0 and GimpUi-3.0
  3a056c3... Allow building vala plugins

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