[gimp] (15 commits) Non-fast-forward update to branch wip/nielsdg/g-define-boxed-type

[Niels De Graef <nielsdg src gnome org>]

The branch 'wip/nielsdg/g-define-boxed-type' 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:

  241887a... libgimpcolor: Use G_DEFINE_BOXED_TYPE()
  ab3f8d6... app: Use G_DEFINE_BOXED_TYPE()
  0700a78... libgimpbase: Use G_DEFINE_BOXED_TYPE()
  bd1b718... libgimpmath: Use G_DEFINE_BOXED_TYPE()

Commits added to the branch:

  74009c8... app: add gimp_image_get_preview_format() (*)
  0ddd333... app: rename gimpimageviewable.[ch] to gimpimageproxy.[ch] (*)
  8d8cc12... app: rename GimpImageViewable to GimpImageProxy (*)
  0e02795... app: in GimpImageProxy, implement GimpPickable (*)
  bce96eb... app: in GimpLineArt, add support for arbitrary buffer exten (*)
  c8b5c81... app: in GimpLineArt, ref input pickable (*)
  02654b0... app: (re-)add GimpDisplayShell::show-all property (*)
  43a1c33... app: add "show all" support to the Bucket Fill tool in line (*)
  05f0f21... Propagate 0ddd3330b8b30091e39ba2b758f26dbd84db0a12 to meson (*)
  c033b34... app: reorder alphabetically file list in meson build. (*)
  2315bc3... Update Catalan translation (*)
  0c59cff... libgimpcolor: Use G_DEFINE_BOXED_TYPE()
  2e7e93f... app: Use G_DEFINE_BOXED_TYPE()
  9bc6305... libgimpbase: Use G_DEFINE_BOXED_TYPE()
  ca53690... libgimpmath: Use G_DEFINE_BOXED_TYPE()

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