Integrate command line database options into configuration.

 * pyrseas/augmentdb.py (AugmentDatabase.apply): Remove opts parameter.
 * pyrseas/cmdargs.py (cmd_parser): Remove config parameter, instead
   use local module object.  (parse_args): New function to implement
   bulk of change.
 * pyrseas/database.py (Database.__init__): Replace database
   parameters by required config parameter.  (Database.{to_map,
   diff_map}): Remove opts parameter.
 * pyrseas/dbaugment.py (main): Add --directory option and TODO note.
 * pyrseas/{dbaugment, dbtoyaml, yamltodb}.py (main): Refactor to call
   new parse_args function, which returns a Config object.
 * pyrseas/testutils.py (PyrseasTestCase.setUp): Add and set up a
   local Config object.  (PyrseasTestCase.database): Initialize
   Database using Config object.  (DatabaseToMapTestCase,
   InputMapToSqlTestCase, AugmentToMapTestCase): Refactor to pass
   options as part of config.