[gegl] (19 commits) ...Merge remote-tracking branch 'origin/meta-json'

[Jon Nordby <jonnor src gnome org>]

Summary of changes:

  7900b22... meta-json: Add initial GeglOperationMetaJson baseclass (*)
  3fd315e... meta-json: Add initial json operation module (*)
  aebd7ac... meta-json: Add to build, depend on glib-json (*)
  d93f6b9... meta-json: Add initial test subgraph (*)
  67faed2... meta-json: Add initial test case (*)
  4f502d2... meta-json: Can set up initial proper (*)
  a5a42c0... meta-json: Can instantiate nodes (*)
  7da609c... meta-json: Can connect nodes of subgraph (*)
  bf1bc22... meta-json: Can redirect properties (*)
  ecb41fb... meta-json: Can set initial properties from file (*)
  562faf9... meta-json: Add a trivial testcase (*)
  3893559... meta-json: Can forward property changes (*)
  4a3f0f2... meta-json: Follow normal module paths for loading (*)
  e815e46... meta-json: Also support GeglColor properties (*)
  405c13f... meta-json: Lookup operation name+description properly (*)
  3a8fc93... meta-json: Fix sensible warnings (*)
  52dcb15... meta-json: Remove debug prints (*)
  aed6865... meta-json: Enable test composition (*)
  564f45b... Merge remote-tracking branch 'origin/meta-json'

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