[gtk] (16 commits) ...transform: Add perspective()

[Benjamin Otte <otte src gnome org>]

Summary of changes:

  0e1a503... transform: Move to GSK (*)
  4916280... transform: Add more API (*)
  3a3c2d1... rendernode: Make the transform node take a GskTransform (*)
  791bf0c... transform: Remove API to poke internals (*)
  3cc84d2... transform: Make category public API (*)
  cf00c36... transform: Split rotate() and rotate3d() class (*)
  e737b42... trasnform: Fix print statement (*)
  979e9be... testsuite: Add a transforms test (*)
  b391aea... widget: Make transform a GskTransform (*)
  70b3411... transform: Remove gsk_transform_identity() (*)
  3545abc... transform: Implement gsk_transform_invert() (*)
  1fecbd4... transform: Store the category in the transform (*)
  bd113aa... transform: Redo querying API (*)
  a8bf5ee... transform: Readd optimization (*)
  dbe5845... rendernode: Implement diffing of transform nodes (*)
  3a3b325... transform: Add perspective()

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