INT-3317: Remove `comparator` from `resequencer`

JIRA: https://jira.spring.io/browse/INT-3317

In addition add `AbstractCorrelatingMessageHandler.discardChannelName` for convenience with JavaConfig

INT-3317: Add `AbstractCorrMH.outputChannelName`

INT-3317: Fix further `BF` population

Also add `MessageFilter.discardChannelName`

Move `XPathExpressionEvaluatingHeaderValueMessageProcessor` to the `xml.transformer.support` package

Additional polishing

Polishing

PR comments.
INT-3320: Update Dependencies

JIRA: https://jira.spring.io/browse/INT-3320
INT-3323: Add poller element to HTTP-outbound

JIRA: https://jira.spring.io/browse/INT-3323

Poller is internally supported in the bean definition of an http outbound gateway and outbound adapter, but it is not supported by their schema. This change attempts to fix the schema.

* Added in schema element for base poller, in both outbound adapter and outbound gateway
* Added in tests to ensure that a PollingConsumer is the instance type
* Polishing `import` for test classes
INT-3322 JDBC i-c-a SpEL Select ParameterSource

JIRA: https://jira.spring.io/browse/INT-3322

Support the use of an ExpressionEvaluatingSqlParameterSource
from the ExpressionEvaluatingSqlParameterSourceFactory as the
`select-sql-parameter-source` for an inbound channel adapter.

Add documentation showing how to construct the bean.

Add a mechanism to disable caching so that the expression is
re-evaluated each time. However, the value should still be
cached between the `hasValue()` and `getValue()` calls.

INT-3322 Polishing; PR Comments