[gegl] (26 commits) Non-fast-forward update to branch wip/rishi/issue-60

[Øyvind "pippin" Kolås <ok src gnome org>]

The branch 'wip/rishi/issue-60' 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:

  9c8f0bf... tools/gegl-imgcmp: fail if no output image

Commits added to the branch:

  9fb676a... Extend configure checks with checks for SDL2 (*)
  d0c939f... Port sdl-display to SDL2 (*)
  17f068e... Port sdl-draw example to SDL2 (*)
  7a2621b... tools: exp_combine fix signedness warning (*)
  fd361b3... gitlab-ci: set XDG_DATA_DIRS in environment for gegl build (*)
  4c561bd... gitlab-ci: use master if babl micro is odd (*)
  9d1e254... configure.ac: depend on babl-0.1.71 (*)
  00c2aad... gitlab-ci: do the min-babl checkout in a shell conditional (*)
  34dba25... gitlab-ci: attempt to use $() instead of `` inside arithmet (*)
  84ae94f... gitlab-ci: conditional execution for babl-min-version (*)
  71d8e28... opencl: in gegl_buffer_cl_iterator_next add gegl_buffer_set (*)
  9ae9320... Update POTFILES.in (*)
  f92aabc... Add vala to the CI env to iron out vala-related build issue (*)
  9a89095... Meson port - integrating merge request !35 (*)
  1858075... gitlab-ci: add meson targets (*)
  2cdec9b... gitlab-ci: remove vestige tempdir from _build (*)
  eba95d4... docs: add skeleton gegl-docs.xml for gtk-doc (*)
  50fad32... meson: depend on babl 0.1.71 (*)
  d6c6c84... meson: add sdl2-display op (*)
  f8b7253... gitlab-ci: give targets more descriptive names (*)
  4d495d0... meson: remove website from configuration summary (*)
  6346ecf... meson: remove PNG reference images before creating tarball (*)
  3f71893... meson: remove some inert lines in gnome.generate_gir (*)
  253a238... Update Catalan translation (*)
  a07cbdf... meson: add export dynamic for the gegl binary, fixing luaji (*)
  633afc6... tools/gegl-imgcmp: fail if no output image

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