POJO used to exchange information on status of the cluster;
that is, settings for nodes that are known by a given server node.
These are exchanged by servers piggy-backed on sync list/pull
requests; and may be POSTed on startup and/or shutdown.
Status of the local node.
Timestamp of time when this message was composed.
Timestamp of last update to aggregated cluster information by the
serving server node.
May be used for diagnostic purposes, or possibly optimizing access.