[gtk] (5 commits) Non-fast-forward update to branch wip/matthiasc/opbuffer

[Matthias Clasen <matthiasc src gnome org>]

The branch 'wip/matthiasc/opbuffer' 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:

  ab53f45... Fix load_vertex_data
  9c40fa0... Some more vertex data reshuffling
  180358d... Cache glyph textures in render nodes
  671ab51... gl: Slightly rework the icon cache api
  f3280a2... gl: Speed up icon cache lookups

Commits added to the branch:

  96c9b2e... Fix load_vertex_data (*)
  8f2b0e3... Some more vertex data reshuffling
  ef9a56d... Cache glyph textures in render nodes
  7792a16... gl: Slightly rework the icon cache api
  90c7ba7... gl: Speed up icon cache lookups

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