Fix various breakage in restbase-cassandra

Our tests are evidently not very good yet; we really need to start testing
stopping & restarting a restbase server.

Changes in detail:
- Version meta tables for consistency with all other tables. Use
  makeSchemaInfo to make sure all expected schema metadata is generated.
- Fix a broken call to _get that didn't pass the table in
- Add some primitive error debug prints; really need to convert this into real
  logging.