Rename and relocate CDC Python examples

Moved the CDC example scripts into the protocol directory and added the .py
suffix. Fixed all references to these scripts.

server/modules/protocol/examples/cdc_users.py

@@ -0,0 +1,21 @@
+#!/usr/bin/env python3
+
+# Copyright (c) 2016 MariaDB Corporation Ab
+#
+# Use of this software is governed by the Business Source License included
+# in the LICENSE.TXT file and at www.mariadb.com/bsl.
+#
+# Change Date: 2019-01-01
+#
+# On the date above, in accordance with the Business Source License, use
+# of this software will be governed by version 2 or later of the General
+# Public License.
+
+import sys, binascii, hashlib, argparse
+
+parser = argparse.ArgumentParser(description = "CDC User manager", epilog = "Append the output of this program to /var/lib/maxscale/<service name>/cdcusers")
+parser.add_argument("USER", help="Username")
+parser.add_argument("PASSWORD", help="Password")
+opts = parser.parse_args(sys.argv[1:])
+
+print((opts.USER + ":") + hashlib.sha1(hashlib.sha1(opts.PASSWORD.encode()).digest()).hexdigest().upper())