[gtk] (7 commits) Non-fast-forward update to branch wip/baedert/box2

[Timm Bäder <baedert src gnome org>]

The branch 'wip/baedert/box2' 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:

  8c78155... box: Remove children list
  56d042c... box: Simplify documentation
  b0a084f... box: Remove gtk_box_pack_end
  e041eed... box: Remove gtk_box_pack_start
  943bf4c... migration guide: Add a paragraph about GtkBox's pack-type
  d2c6b51... colorchooser: Remove extra custom color

Commits added to the branch:

  4ddbb8c... box: Remove children list
  67d2502... box: Simplify documentation
  5d502f7... box: Remove gtk_box_pack_end
  10ecc00... box: Remove gtk_box_pack_start
  4867d4c... migration guide: Add a paragraph about GtkBox's pack-type
  3aec971... colorchooser: Remove extra custom color
  3870e28... popover demo: Fix size-allocate callback signature