[mutter] (12 commits) Non-fast-forward update to branch gbsneto/effects-paint-nodes

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

The branch 'gbsneto/effects-paint-nodes' 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:

  89777fd... clutter/effect: Don't expose pre and post paint helpers
  4e9bc02... Introduce ClutterEffectNode
  6d52766... clutter/effect: Add paint_node vfunc
  4c4dd9b... clutter/offscreen-effect: Clear framebuffer on pre_paint
  cc4c89b... clutter/offscreen-effect: Simplify paint
  aefcf74... clutter/paint-nodes: Don't skip pipeline node constructor
  9bab4c9... clutter/paint-nodes: Add new ClutterLayerNode API
  b5ae10d... clutter/paint-nodes: Push and pop framebuffer even without 
  744ee38... clutter/paint-nodes: Add serialization to layer node
  cfd73cf... Introduce ClutterBlitNode

Commits added to the branch:

  dbff32e... clutter-backend: Default to scale 1 (*)
  0f1289e... clutter/effect: Don't expose pre and post paint helpers
  e8f9d09... Introduce ClutterEffectNode
  35af306... clutter/effect: Add paint_node vfunc
  0d51678... clutter/offscreen-effect: Clear framebuffer on pre_paint
  e0a8e82... clutter/offscreen-effect: Simplify paint
  9d7dbdd... clutter/paint-nodes: Add opacity overriding to ClutterActor
  22aa5ee... clutter/paint-nodes: Don't skip pipeline node constructor
  969988e... clutter/paint-nodes: Add new ClutterLayerNode API
  7370909... clutter/paint-nodes: Push and pop framebuffer even without 
  c0ab924... clutter/paint-nodes: Add serialization to layer node
  fc185d9... Introduce ClutterBlitNode

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