Our current use of leveldb is not optimal, as the leveldb is not supported by upstream for production environments.

atomix.io has a SegmentedJournal class, which looks like a very good match for Akka's persistence semantics, while potentially allowing direct integration into sal-akka-raft (as it really matches RAFT log semantics).

Add a custom Akka Persistence Journal implementation based on SegmentedJournal to complement our custom SnapshotStore implementation.