Merge branch 'stable-3.1' into stable-3.2

* stable-3.1:
  Propagate FetchRefReplicatedEvent
  Send small refs as a fetch call payload
  Send ref content as a fetch call payload
  Index change upon propagation
  Propagate FetchRefReplicatedEvent upon a Ref fetch

Change-Id: I89e4d6104a590a10ed2ecd709d0595f59d1f7f99