[gtk] (5 commits) Non-fast-forward update to branch redo-superset

[Matthias Clasen <matthiasc src gnome org>]

The branch 'redo-superset' 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:

  f593be4... wip: Redo change computation
  62daabe... Drop unused code
  29ff92e... Revert "Remove no longer used code"
  d90e13e... Bring back the reserved bit
  2cc1880... Move change computation back to the tree

Commits added to the branch:

  2c317b9... Revert "Remove no longer used code"
  ee2b160... Bring back the reserved bit
  6cc5331... Redo the way we compute change
  20dddd8... Go back to the tree for computing change
  e16a3b6... Remove no longer needed code