Add CASSANDRA_REPLICATION_FACTOR environment variable and
--cassandra-replication-factor CLI argument to cassandra_config.py.
Update all four table store constructors (ConfigTableStore,
KnowledgeTableStore, LibraryTableStore, IamTableStore) to accept
an optional replication_factor parameter and use it in keyspace
creation CQL queries.
Thread the replication factor through all service constructors:
Configuration, KnowledgeManager, Librarian, IamService, and
knowledge store Processor.
* Plugin architecture for messaging fabric
* Schemas use a technology neutral expression
* Schemas strictness has uncovered some incorrect schema use which is fixed
