[gtk] (6 commits) Non-fast-forward update to branch prop-list

[Matthias Clasen <matthiasc src gnome org>]

The branch 'prop-list' 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:

  25ae274... Add GtkDropDown
  915f979... inspector: Use dropdowns in property editor
  78be704... inspector: Use dropdown for attribute mapping
  7189628... inspector: Use dropdown for controllers
  144d918... inspector: Use dropdown for size groups
  8c5ec8d... inspector: Use dropdowns in the visual page

Commits added to the branch:

  3eab19a... Add GtkDropDown
  4e7c811... inspector: Use dropdowns in property editor
  50c97ff... inspector: Use dropdown for attribute mapping
  3842b02... inspector: Use dropdown for controllers
  171f64f... inspector: Use dropdown for size groups
  9425ab7... inspector: Use dropdowns in the visual page