INT-2516 Warn for Invalid request-payload-type

Issue initialization warning on inappropriate
request-payload-type attribute on Http Inbound Endpoint.
Merge pull request #478 from olegz/INT-2516
INT-2459 Add Support for TCP Failover

Implemented a ConnectionFactory that wraps a list
of connection factories, used to fail over if
a connection fails.

INT-2459 Polishing

Rebase; fix test; move boolean resets to finally block
in server factories.

INT-2459 Polishing

PR Review

Fix a test that could block indefinitely when error
in code under test.
Merge pull request #482 from garyrussell/INT-2459

* INT-2459:
  INT-2459 Add Support for TCP Failover
INT-2540 AbstractJmsChannel wasn't Marked Abstract

Class should have been abstract. In any case,
it could not be used in any meaningful way
as a concrete class so changing it would
not represent a breaking change.
Merge pull request #484 from garyrussell/INT-2540

* INT-2540:
  INT-2540 AbstractJmsChannel wasn't Marked Abstract
INT-2604 Remove Deprecated Header

The IPHeaders.CONNECTION_SEQ was replaced by the
standard sequenceNumber header (when applySequence is true)
in 2.1, in order to facilitate resequencing using the
standard resequencer.

This header was deprecated at that time. It is now
removed.

Users that were relying on this header should set
applySequence to true on the connection factory.
Merge pull request #485 from garyrussell/INT-2604

* INT-2604:
  INT-2604 Remove Deprecated Header
INT-1029: Support for outbound-gateways in chain

XSD refactoring: remove use="required" from 'request-channel' attribute of all 'outbound-gateways'
Tests for all 'outbound-gateways' inside the <chain>
Merge pull request #483 from artembilan/INT-1029

* INT-1029:
  INT-1029: Support for outbound-gateways in chain
INT-2590 Add TestingUtility

Added testing utility from samples to provide a tool for
users to wait for servers to start during tests.

Also refactored all tests that had similar code to use
this class.

Also corrected two failing tests that needed this wait.
Merge pull request #487 from garyrussell/INT-2590

* INT-2590:
  INT-2590 Add TestingUtility
INT-1929 Custom Mail SearchTerms

Add support for overriding default SeatchTerms in ImapMailReceiver

INT-1929 PR comments

Polish Docs
Merge pull request #481 from olegz/INT-1929
INT-1760, INT-1759 Http outbound gateway response type

Change the default expected response type to ResponseEntity

Add support for expected-response-type-expression attribute
to accept SpEL to determine expected response type.

INT-1760, INT-1759 add documentation.

INT-1760, INT-1759 polished javadocs and schema doc

INT-1760, INT-1759 more polishing

INT-1760, INT-1759 polished documentation based on PR

INT-1760 Polishing

Fix Chain test.
Merge pull request #480 from olegz/INT-1760
INT-1132: DelayHandler: rescheduling support

- Add support for DelayHandler reschedule persisted Messages on startup
- Change DelayHandler dependency to MessageGroupStore
- Add required DelayHandler.messageGroupId property
- Make registered by SI-namespace TaskScheduler as default for DelayHandler
- Remove 'required' from delayer xml-attribute 'default-delay' as redundant
- Additional refactoring & polishing around <delayer>
- Polishing delayer's Tests
- Test about 'rescheduling'
- Integration test about 'rescheduling' with JdbcMS
INT-1132: polishing based on PR comments

Introduce Delayer's internal Message Header 'REQUEST_DATE' to store arrival time of requested Message.
Used to determine real 'schedule' Date for message to avoid full delay period after App restart.
Polishing test for correct logic about 'REQUEST_DATE' on scheduling.
INT-1132: support SmartLifecycle for DelayHandler

Introduce DelayHandlerFactoryBean, which encapsulate logic about creation DelayHandler, implements SmartLifecycle as delegation to DelayHandler
DelayHandlerFactoryBean has static 'usedDelayersTaskSchedulers' to store TaskSchedulers bean names to check unique pair: DelayHandler + TaskScheduler
DelayHandler: encapsulate 'requestDate' into DelayedMessageWrapper
Polishing tests
INT-1132: Delayer's SmartLifecycle improvement

Additional logic about SmartLifecycle.
Tests for DelayerParser about SmartLifecycle attributes.
Polishing existing delayer's test for SmartLifecycle support.