[gnome-shell] (11 commits) ...notificationDaemon: Write notifications out to disk

[Jasper St. Pierre <jstpierre src gnome org>]

Summary of changes:

  88d0731... messageTray: Replace setButtonSensitive by simply returning (*)
  5023542... messageTray: Split out addButton to allow consumers to pass (*)
  5f081b8... messageTray: Remove useActionIcons feature (*)
  43f4682... messageTray: Make addButton/addAction take a callback (*)
  8ee0ef2... messageTray: Don't always open the source when clicking on  (*)
  27a86a4... notificationDaemon: Move nextNotificationId inside the daem (*)
  394743e... notificationDaemon: Rename the existing implementation to t (*)
  e0b87f1... notificationDaemon: Implement the new GTK+ notifications AP
  c9b73ac... shell-global: Handle empty variants better
  1ac4ab7... shell-global: Add new APIs for saving/loading persistent st
  9d8fb19... notificationDaemon: Write notifications out to disk

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