* when using remember entities with ddata mode the set of
shards were not saved in durable storage and therefore the
remembered entities were not loaded until the first message
was sent to the shard
* the coordinator stores the set of shards in a durable GSet
* loaded when the coordinator is started and added to the State,
rest is already taken care of via the unallocatedShards Set in
the State
* when new shards are allocated the durable GSet is updated if it
doesn't already contain the shard identifier
* one Replicator per configured role
* log LMDB directory at startup
* clarify the imporantce of the LMDB directory
* use more than one key to support many entities
