[gtk] (3 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:

  8be6159... Add a cursor-aspect-ratio setting
  abce542... css: Fix an oversight in style change computation

Commits added to the branch:

  f15a34c... gdk: Handle small final sigma in gdk_keyval_convert_case (*)
  f84fdfc... Merge branch 'sigma' into 'master' (*)
  621120d... css: Fix an oversight in style change computation

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