[gtk] (11 commits) Non-fast-forward update to branch overlay-layout

[Matthias Clasen <matthiasc src gnome org>]

The branch 'overlay-layout' 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:

  6e4cbed... overlay: Use a layout manager
  37ca6b6... builder-tool: Convert overlay child properties
  38a926e... Convert ui files
  4f5b830... builder-tool: Small refactoring

Commits added to the branch:

  65c394d... Document how to define layout manager properties (*)
  3d6a456... Add release info to our demo apps (*)
  3f0f7c7... Connect LayoutManager to LayoutChild (*)
  ecba428... Add missing handler for <layout> elements in UI files (*)
  208cae2... Do not leak unapplied layout properties (*)
  18d1ea1... Merge branch 'layout-child-type' into 'master' (*)
  0f7ca7e... Update POTFILES.in (*)
  866640c... overlay: Use a layout manager
  fc3cae3... builder-tool: Convert overlay child properties
  8d99316... builder-tool: Small refactoring
  700183e... Convert ui files

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