[gtk] (3 commits) Non-fast-forward update to branch wip/otte/conic

[Benjamin Otte <otte src gnome org>]

The branch 'wip/otte/conic' 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:

  d1e8772... glrenderer: Emit more useful error messages
  e7fdd9d... rendernode: Fix some wrong constants for conic gradients
  1a82e41... glrenderer: Implement a shader for conic gradients

Commits added to the branch:

  c04a731... glrenderer: Emit more useful error messages
  ffbd8bd... rendernode: Fix some wrong constants for conic gradients
  49dc714... glrenderer: Implement a shader for conic gradients