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_kafka_producer.py

@@ -0,0 +1,61 @@
+#!/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.
+
+# This program requires the kafka-python package which you can install with:
+#
+#     pip install kafka-python
+#
+
+import json
+import sys
+import argparse
+from kafka import KafkaProducer
+
+parser = argparse.ArgumentParser(description = "Publish JSON data read from standard input to a Kafka broker")
+parser.add_argument("-K", "--kafka-broker", dest="kafka_broker",
+                    help="Kafka broker in host:port format",
+                    default=None, required=True)
+parser.add_argument("-T", "--kafka-topic", dest="kafka_topic",
+                    help="Kafka topic where the data is published",
+                    default=None, required=True)
+
+opts = parser.parse_args(sys.argv[1:])
+decoder = json.JSONDecoder()
+rbuf = bytes()
+producer = KafkaProducer(bootstrap_servers=[opts.kafka_broker])
+
+while True:
+   try:
+      buf = sys.stdin.read(128)
+
+      if len(buf) == 0:
+         break
+
+      rbuf += buf.encode()
+
+      while True:
+         rbuf = rbuf.lstrip()
+         data = decoder.raw_decode(rbuf.decode('ascii'))
+         rbuf = rbuf[data[1]:]
+         producer.send(topic=opts.kafka_topic, value=json.dumps(data[0]).encode())
+
+   # JSONDecoder will return a ValueError if a partial JSON object is read
+   except ValueError as err:
+      pass
+
+   # All other errors should interrupt the processing
+   except Exception as ex:
+      print(ex)
+      break
+
+producer.flush()