INT-3336 Add error-channel to MQTT m-d-c-a

JIRA: https://jira.spring.io/browse/INT-3336

Previously exceptions thrown in a flow downstream of a
message-driven-channel-adapter were not logged and thrown
back to the client, causing the connection to drop and
reconnect.

Add `error-channel` to the adapter to allow normal
error handling. If no error channel, catch and log
the unhandled exception.

Add `adapter.stop();` in the end of 'real' tests to close the mqtt-connection
INT-3336 Fix MQTT Test Rule

JIRA: https://jira.spring.io/browse/INT-3336

Disconnect the client after verifying the broker is available.
Change the rule to a class level rule in DownstreamExceptionTests.
Test, Javadoc Cleanup

* Remove an unnecessary test.
* Fix timing in header channel registry test.
* Fix Javadocs in VetoCapableInterceptor
INT-3343 Bump JSch, Hibernate Versions

JIRA: https://jira.spring.io/browse/INT-3343
Add Bamboo Status to README
INT-3342 Allow Custom TypeLocator for SpEL

JIRA: https://jira.spring.io/browse/INT-3342

Allow customization of the `TypeLocator` used by SpEL
`EvaluationContext`s throughout the framework.
INT-3331: add `ChannelSecurityInterceptorFB`

JIRA: https://jira.spring.io/browse/INT-3331
INT-3331: PR comments and others

* Register `ChannelSecurityInterceptorBeanPostProcessor` as a `BeanDefinition` (not `BPP`)
* Get `ChannelSecurityInterceptor`s from `ChannelSecurityInterceptorBeanPostProcessor#afterPropertiesSet()`
* Make `ChannelSecurityInterceptor` `final` to disallow to subclass it for unexpected issues
* Provide more convenience to the `ChannelSecurityInterceptorFactoryBean` - to allow to use it from xml configuration