Adding custom configuration support

This change updates the KMIP client to support the custom selection of
client configuration options. This makes it easy to dynamically create
clients that connect to different backends. All unit demos have been
updated to support this feature.

kmip/demos/units/discover_versions.py

@@ -32,15 +32,16 @@ if __name__ == '__main__':
 
     username = opts.username
     password = opts.password
+    config = opts.config
 
-    # Build and setup logging and needed factories
+    # Build and setup logging
     f_log = os.path.join(os.path.dirname(__file__), os.pardir, os.pardir,
                          'logconfig.ini')
     logging.config.fileConfig(f_log)
     logger = logging.getLogger(__name__)
 
     # Build the client and connect to the server
-    client = KMIPProxy()
+    client = KMIPProxy(config=config)
     client.open()
 
     result = client.discover_versions()