INT-2753 - Add CONTRIBUTING.md
Copied from the Contributor Guidelines wiki document [1] in order to
take advantage of GitHub's new integrated support for displaying a link
to contributor guidelines when issuing a pull request [2].

[1]: https://github.com/SpringSource/spring-integration/wiki/Contributor-Guidelines
[2]: https://github.com/blog/1184-contributing-guidelines

For reference see: https://jira.springsource.org/browse/INT-2753
Merge pull request #645 from ghillert/INT-2753

  INT-2753 - Add CONTRIBUTING.md Copied from the Contributor Guidelines wiki document [1] in order to take advantage of GitHub's new integrated support for displaying a link to contributor guidelines when issuing a pull request [2].
INT-2781 Retry Advice; Fix Recovery For Zero Tries

Retry Advice (ErrorMessageSendingRecoverer) tried to send a message
with a null payload when the RetryPolicy allowed zero attempts.

Create a MessageHandlingException with the failedMessage, when
no attempts were made to call the handler.
Merge pull request #643 from garyrussell/INT-2781

  INT-2781 Retry Advice; Fix Recovery For Zero Tries
INT-2776 Add Sender's UDP Port To Headers

User code can use the existing host and this new
header to send a reply over UDP.
Merge pull request #641 from garyrussell/INT-2776

  INT-2776 Add Sender's UDP Port To Headers
INT-2764 added what's new for Redis/Mongo adapters
Merge pull request #649 from olegz/INT-2764

  INT-2764 added what's new for Redis/Mongo adapters
INT-2777 TransactionSynchronization

Ensured that bindings of the resource only happen if TransactionSynchronizationFactory is not null
Add documentation describing the expectation for the unbinding of the resource.

INT-2777 Polishing

Don't set up holder if it's not used.

Doc fixes.
Merge pull request #647 from olegz/INT-2777
INT-2773: Fix `AmqpOutboundEndpoint`'s properties

* make `AmqpOutboundEndpoint` 'exchangeName' & 'routingKey' **null** by default
* some polishing for `AmqpOutboundEndpoint`
* verification tests for parameters of `com.rabbitmq.client.Channel#basicPublish`

JIRA: https://jira.springsource.org/browse/INT-2773

INT-2773 Polishing - Allow Override to ""

Previously, there was no way to revert to the previous
behavior by specifying an empty string for the attribute(s).

Add test to verify setting attributes to "" overrides template.
Merge pull request #640 from artembilan/INT-2773
INT-2280 fixed broken JDBC test
Fix JdbcMessageStoreChannelTests.testSendAndActivateWithRollback as well as others by changing poller interval.

Poller was polling too quickly, so even the slightest delay before assertion would result in another Message in the Service.messages thus the intermittent assertion error.

INT-2280 Polishing

Don't add retries to message list.
Merge pull request #648 from olegz/INT-2280
INT-2782 Fix spring-retry Import-Package

Bundlor: move retry packages above catch-all org.springframework.*
in the import template.
Merge pull request #651 from garyrussell/INT-2782

  INT-2782 Fix spring-retry Import-Package
INT-2786 Do not Provide Fixed XMPP Resource String

Previously, the connection resource was hard-coded to 'Smack' by
default.

According to RFC 6120 section 7.6.  Server-Generated Resource Identifier
if the connecting client does not provide resource string, server will
generate RANDOM one for it.
Smack API allows this by providing null resource in
XMPPConnection#login(username, password, resource) call.
See Smack's SASLAuthentication documentation.

Tested with XMPP sample (including default resource and configuring
as 'Smack').
Merge pull request #650 from smokku