Keep status_changed_at in container databases current with status changes that
occur as a result of container creation, deletion, or re-creation.
Merge container put/delete/created timestamps when handling replicate
responses from remote servers in addition to during the handling of the
REPLICATE request.
When storage policies are configured on a cluster send status_changed_at,
object_count and storage_policy_index as part of container replication sync
args.
Use status_changed_at during replication to determine the oldest active
container and merge storage_policy_index.
DocImpact
Implements: blueprint storage-policies
Change-Id: Ib9a0dd42c271145e641437dc04d0ebea1e11fc47
81bc31e6ec