[gegl] (4 commits) Non-fast-forward update to branch wip/pippin/pipeline

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

The branch 'wip/pippin/pipeline' 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:

  7ef2460... gegl: add pipeline infrastructure
  8bddf7e... gegl: add pipeline storage to opcontext
  9d3b1c2... gegl: replace processing in point ops with pipeline
  c9773e0... buffer: add new iterator api that can take more buffers
  3b7a5c1... pipeline: port to new iterator api

Commits added to the branch:

  e0585e9... buffer: add new iterator api that can take more buffers
  0641b0c... gegl: add pipeline infrastructure
  ed78030... gegl: add pipeline storage to opcontext
  6223ed2... gegl: replace processing in point ops with pipeline