Process KayVee reads out of the local database

[allengeorge]

Right now all KayVee reads are processed only after a GET or ALL command is issued to the Raft cluster. This provides read-after-write consistency for a client and is equivalent to Zookeeper's sync primitive. This prevents fast reads, however.

It would be ideal for GET or ALL to be serviced by any follower out of its local database, unless the client explicitly requests read-after-write consistency. This requires the following enhancements: #1 and #6.