[gtk] (14 commits) Non-fast-forward update to branch wip/baedert/for-master

[Timm Bäder <baedert src gnome org>]

The branch 'wip/baedert/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:

  691cbe7... checkbutton: Use a box layout
  043ac99... radiobutton: Fix a warning in a code sample
  4073199... adwaita: Use border-spacing to style checkbuttons
  5d46dec... Adwaita: make links in infobars legible
  c471504... Adwaita: Add color defines from 3.24
  ba071ba... Tiny refactoring
  b1e6b94... Adwaita: Blue check/radiobuttons
  6f7e61a... modelbutton: Create accel label on demand
  3e56de8... modelbutton: Remove end_box
  b014330... modelbutton: Replace map() with root()
  1aa0189... modelbutton: Use a box layout
  ec69338... button: Remove unused signal enum members
  044047d... modelbutton: Rework

Commits added to the branch:

  b1434e5... checkbutton: Use a box layout
  c3cf5c4... radiobutton: Fix a warning in a code sample
  c9569f5... adwaita: Use border-spacing to style checkbuttons
  8917be5... Adwaita: make links in infobars legible
  fca1099... Adwaita: Add color defines from 3.24
  6549ab2... Tiny refactoring
  b833a63... Adwaita: Blue check/radiobuttons
  15db4bf... modelbutton: Create accel label on demand
  e474139... modelbutton: Remove end_box
  f314032... modelbutton: Replace map() with root()
  4e82357... modelbutton: Use a box layout
  aa47a6c... button: Remove unused signal enum members
  3770ebd... modelbutton: Rework
  052cbcc... widget: Plug layout manager leak