Merge changes If9b31b3b,Iea400614,I9567aaf5,I6696029f,I3d4f434e, ...

* changes:
  Don't show new groups until their children inflate
  Cleanup PreparationCoordinator a bit
  Add onCleanup() method to Pluggables
  Introduce GroupEntryBuilder
  NotificationEntryBuilder can modify existing entries
  Move creationTime into ListEntry (from NotifEntry)