[gtk] (23 commits) Non-fast-forward update to branch matthiasc/for-master

[Matthias Clasen <matthiasc src gnome org>]

The branch 'matthiasc/for-master' 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:

  1e259c1... NEWS: Updates
  66bde8d... Silence a compiler warning
  78f5545... gsk: Document radial gradient api
  97874a0... wayland: Match header and doc arguments
  c67e9b6... docs: Fix a typo
  318baec... snapshot: Document radial gradient apis
  28e85db... statusbar: Remove a misleading doc comment
  5be5f42... docs: Document various entry ::activate signals

Commits added to the branch:

  6887d0c... glrenderer: Move ProgramState into Program (*)
  7edcd17... gl: Properly report error if shader linking fails (*)
  9460d01... gl backend: Add line numbers to source in glsl compilation  (*)
  bacb3af... gl: Add some namespacing to the preamble symbols (*)
  16cdb33... shadertoy demo: Fix GLSL on GLES (*)
  a91b6b4... css: Move the last parser api to the new header (*)
  645fc6a... GtkWindow: Create renderer before realizing child widgets (*)
  6e9b58b... gsk: Add more shader debug spew (*)
  7ea755e... Add GskGLShaderNode and GskGLShader (*)
  950cc41... GtkSnapshot: Add gtk_snapshot_push_glshader() (*)
  4d69728... Support GLShaderNode in backends (*)
  8bcb031... gtk-demo: Add GskGLShaderNode demo (*)
  e76cb3e... gtk-demo: Add a shader paintable to the fishbowl (*)
  4e55220... Add some shader tests (*)
  2e5caa6... Merge branch 'glshader-node' into 'master' (*)
  91c3edb... NEWS: Updates
  3af249c... Silence a compiler warning
  07c338b... gsk: Document radial gradient api
  165768b... wayland: Match header and doc arguments
  f129941... docs: Fix a typo
  c897daf... snapshot: Document radial gradient apis
  aac9414... statusbar: Remove a misleading doc comment
  4a2c817... docs: Document various entry ::activate signals

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