[jvstm-lf] Measure resend round-trip time
[jvstm-lf] Send only new benign commits in DeltaCommitRequest
[jvstm-lf] Improve list of benign: send only NEW deltas and don't skip any entry in CommitRequests queue.
[core] Fix schema version in jgroups config file
[core] Upgrade JGroups 3.3.1.Final -> 3.4.0.Final
[jvstm-lf] Substitute JGroups for Hazelcast as the group communication system
[jvstm-lf] Substitute JGroups for Hazelcast as the group communication system (part 2)
[jvstm-lf] Only committer thread writes mapping txVersion->commitId