[libadwaita] (7 commits) Non-fast-forward update to branch wip/exalm/paned-fix

[Alexander Mikhaylenko <alexm src gnome org>]

The branch 'wip/exalm/paned-fix' 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:

  2fb595d... stylesheet: Fix paned separators

Commits added to the branch:

  db5bffd... stylesheet: Simplify window borders and outline (*)
  156b55e... style-manager: Properly reset animations (*)
  fb9831f... doc: Mention content-view and related colors in migration g (*)
  ef0479c... stylesheet: Redo selection mode checks (*)
  73e64bc... demo: Add a checkbutton.selection-mode demo (*)
  02802d8... stylesheet: .osd refinements (*)
  f9c418d... stylesheet: Fix paned separators

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