[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:

  860a515... glrenderer: Emit more useful error messages
  fde857f... rendernode: Fix some wrong constants for conic gradients
  bd0ffb0... glrenderer: Implement a shader for conic gradients

Commits added to the branch:

  c907ad8... glrenderer: Emit more useful error messages
  fac5fba... rendernode: Fix some wrong constants for conic gradients
  2c1bd39... glrenderer: Implement a shader for conic gradients