[gtk] (3 commits) Non-fast-forward update to branch glshader-paintable

[Matthias Clasen <matthiasc src gnome org>]

The branch 'glshader-paintable' 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:

  8e8fcfd... gtk-demo: Add a shader paintable demo
  4a8a686... gtk-demo: Add a shader paintable to the fishbowl

Commits added to the branch:

  2bb196b... Work around linker issues
  4220c6e... gtk-demo: Add a shader paintable demo
  9c00609... gtk-demo: Add a shader paintable to the fishbowl