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

[Alexander Mikhaylenko <alexm src gnome org>]

The branch 'wip/exalm/background-colors' 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:

  da9f326... stylesheet: Make everything recolorable
  a3e6212... stylesheet: Stop referring to color variables from _default
  f8d180a... stylesheet: Split base and defaults

Commits added to the branch:

  76f3028... stylesheet: Drop toolbar background
  9fe1ce4... stylesheet: Use headerbar border for headerbar separators
  13288fd... stylesheet: borders_color -> border_color
  fba3458... stylesheet: Rename base/text/bg/fg_color variables
  afc8423... stylesheet: Make everything recolorable
  240ebb5... stylesheet: Stop referring to color variables from _default
  afaaa89... stylesheet: Split base and defaults