[gtk] (16 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:

  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
  f129968... widget-factory: Skip xml files in background selection dial
  cab63df... dialog: Fix action button rearrangement

Commits added to the branch:

  5b45e82... radiobutton: Fix a warning in a code sample
  ca711e3... adwaita: Use border-spacing to style checkbuttons
  3843167... Adwaita: make links in infobars legible
  170b19b... Adwaita: Add color defines from 3.24
  b1c54ea... Tiny refactoring
  28e4bcf... Adwaita: Blue check/radiobuttons
  b3cc07b... modelbutton: Create accel label on demand
  c6c3307... modelbutton: Remove end_box
  3cf3575... modelbutton: Replace map() with root()
  8cf418b... modelbutton: Use a box layout
  25b8bdd... button: Remove unused signal enum members
  00ee798... modelbutton: Rework
  eac4eee... widget: Plug layout manager leak
  316886e... widget-factory: Skip xml files in background selection dial
  eded7fd... dialog: Fix action button rearrangement
  75859b6... label: Use TRUE/FALSE instead of 1/0