Change IndexCommitNotice so that rather than describe a range of sequence numbers, it describes a single seqNum up to which entries are committed. This is better because the first commit notice issued by a Replicator has no way of knowing the lower end of its sequence number range; it only indicates awareness that entries ARE committed up to a certain point, not that a certain set of entries have JUST been committed.
Add method getCommittedEntryChannel to Replicator interface, and stub it out in implementing classes. This method will be used to implement c5#283
Add failing tests for issuing committed entries
ReplicatorInstance WIP adding pendingEntries array and altering the commit logic
+fixup