Cluster: cluster_my_epoch added to CLUSTER INFO output.
Cluster test: check master -> slave role switch.
Cluster test: unit 02 should wait for failover.
Cluster test: 02 unit more reliable waiting for slave sync.
Cluster test: new unit 03, failover loop stress testing.
Cluster test: added show-redis-logs command in the interactive console.
Cluster test: better failover detection in unit 03.
Cluster test: unit 03, check epochs correctness.
Cluster: log when a master denies a failover auth.
Cluster: log configEpoch updates to myself.
Cluster: log granted failover authorizations.
Cluster test: set config epochs when creating clusters.
Cluster: better comment for clusterSendFailoverAuthIfNeeded() epoch test.
Cluster: fix an error message when logging failover auth denied.