[gtk] (4 commits) Non-fast-forward update to branch constraint-list-model

[Matthias Clasen <matthiasc src gnome org>]

The branch 'constraint-list-model' 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:

  6a333ae... constraint editor: Implement saving
  35ef807... constraints editor: Stop naming constraints

Commits added to the branch:

  a956ee4... flattenlistmodeL: Compute items-changed position properly
  9a5ea0a... constraint editor: Implement saving
  2b54b8a... constraints editor: Stop naming constraints
  8d2f1f4... constraint editor: Implement loading