XD-2323 Fix Batch replyChannel Header

JIRA: https://jira.spring.io/browse/XD-2323

Spring Integration 4.1.0 incorrectly mapped the `replyChannel`
header as a String, preventing the replacement with
the `xdReplyChannel` (transmitted as a String to the slave).

See INT-3555.

Set `overwrite="true"`.
Comment out externalized property in servers.yml
  - The properties in servers.yml should be commented out
for the end users to uncomment/configure.
XD-2296 Configure enable/disable message rate monitoring

 - Add new property `xd.messageRateMonitoring.enabled`
 - Gather message rates metrics only if this property is set to `true`
 - Set the client side property to `true` as we want this to be driven
from server side
XD-2148 XD-2149 add distShellZip gradle task

- remove unused libs from shell distro

- update xd-shell and xd-shell.bat

- add jars from spring-xd/xd/lib
Fix RabbitMessageBusTests

The AMQP endpoints now hold expressions internally as a
SpEL Expression instead of a String. Some tests were
examining these Strings.

Change tests to use expression.getExpressionString().
Fix enableMessageRates property type

 - Use `String` instead of `boolean`
XD-2148 XD-2149 add distShellZip gradle task

- fixing classifier for published zip file
XD-2216 Update Spring Framework, Integration, AMQP

Spring Framework 4.1.2
Spring Integration 4.1.0
Spring AMQP 1.4.0
Fix duplicate entry in ModuleDescriptor String
XD-2320 UI: Create a dedicated Launch Page for Jobs

* Create separate page to launch jobs
* Improve form validation
XD-2321 UI: Create a dedicated scheduling page for Jobs

* Add dedicated page for scheduling jobs
* Improve form design and UX
* Improve validation

XD-2321 Realigned form so that error icon works
XD-2319 - Include python modules in distribution and various improvements

* Removed unnecessary code in stream.py
* Added Sink object
* Updated stream.py
* Changed default encoding to CRLF
* Make stream.py python/python3 version agnostic
XD-2103 Add Kafka Sink

 - Add kafka sink module with kafka producer context configuration
   - This module depends on kafka SI integration extensions
 - Add sink module options
 - Add external Kafka producer properties file
   - These properties are added to the producer context when configured.
Update Kafka source StringDecoder

  - use StringDecoder from SI extensions
replaced in line conditional with if else for backward compatibility