[gtk] (8 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:

  7cc5e79... centerlayout: Some spacing-related fixes

Commits added to the branch:

  7428731... Merge branch 'matthiasc/for-master' into 'master' (*)
  f71c9a2... Updated Spanish translation (*)
  e61f516... gtkspinbutton: Group up/down button gestures with self (*)
  2e72b66... Merge branch 'wip/carlosg/start-spinbutton-start' into 'mas (*)
  2ac51ad... centerlayout: Some spacing-related fixes
  17dcb10... Add a reftest for box layouts
  08f5812... Add a reftest for grid layouts
  c890d59... Add reftests for center layout

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