[gtk+] (8 commits) Non-fast-forward update to branch wip/baedert/progressbar

[Timm Bäder <baedert src gnome org>]

The branch 'wip/baedert/progressbar' 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:

  bc73b74... box: Remove fill child property
  27fd28f... testboxcss: Fix custom CSS
  6796eb1... actionbar: Add explicit center widget
  2f6b8d4... container: Remove include_internals parameter from forall
  641c887... overlay: Ensure proper child widget order
  f91076d... box: Remove center child
  4e0a12c... testsuite: Add widget ordering test case
  bff4e03... box: Compute clips directly

Commits added to the branch:

  33574bd... box: Remove fill child property
  be7357a... testboxcss: Fix custom CSS
  e8fb162... actionbar: Add explicit center widget
  a3b2cce... container: Remove include_internals parameter from forall
  b86196f... overlay: Ensure proper child widget order
  862fdca... box: Remove center child
  d0a3466... testsuite: Add widget ordering test case
  ef6b02d... box: Compute clips directly