INT-3231: Fix Tail setters types for SPR 3.1.x

JIRA: https://jira.springsource.org/browse/INT-3231
INT-3228: Remove Previous versions' Deprecations

JIRA: https://jira.springsource.org/browse/INT-3228

Remove elements that were deprecated in earlier
versions; see the migration guide for more information

https://github.com/spring-projects/spring-integration/wiki/Spring-Integration-2.2-to-3.0-Migration-Guide

INT-3228: Revert FileTransferMH#setTempDirectory
INT-3221: Deprecate MessageTransformingCI

JIRA: https://jira.springsource.org/browse/INT-3221
INT-3220,INT-3224: Fix Twitter & Channel docs

JIRA:
https://jira.springsource.org/browse/INT-3224
https://jira.springsource.org/browse/INT-3220
INT-3221 Polishing

Remove unused import.

JIRA: https://jira.springsource.org/browse/INT-3221
INT-3230 Added support for 'load-balancer-ref' attribute
 of the 'channel' element. Added tests and updated documentation

INT-3230 addressed PR comments
INT-3232: RedisQMDE: Polish Log Exceptions

JIRA: https://jira.springsource.org/browse/INT-3232

Previously, in the `RedisQueueMessageDrivenEndpoint` all `Exceptions` on `rightPop` operation
were logged with `error` level independently of the state of the Endpoint.

Add `if...else` and log with `debug`, if the Endpoint isn't active and don't publish the event.
INT-3043 Add Endpoint Quick Reference Table

JIRA: https://jira.springsource.org/browse/INT-3043

INT-3043: Polishing
Update Default Spring Dependency to 3.2.6

Also usable with Spring 4.0.0 and 3.1.4.
INT-3233 NIO, Windows 7 and Java 7/8

JIRA: https://jira.springsource.org/browse/INT-3233

With Windows 7 and Java 7/8 closing a server channel does
not close the underlying socket. Closing the Selector does
close the socket.

It is not clear why this is needed, given that a selector can
be used for multiple sockets.

However, we only use the server side selector for a single
server socket so there is no detriment in closing it.

Also close the selector on the client side (even though it is
used for multiple sockets, because we are stopping the factory
anyway and all sockets will be closed).

However, closing the selector opens us up to 'ClosedSelectorException's
in several places. Add catch blocks to deal with this exception, and only
log an error if the factory is active.

While debugging this issue, I found that a number of (older) tests
left threads running, sockets open etc.

INT-3233 Polishing - PR Comments
INT-3235 Make GatewayMethodMetadata Public

JIRA: https://jira.springsource.org/browse/INT-3235

Unable to programmatically wire header expressions or method-specific
properties into a GatewayProxyFactoryBean.

The GPFB has public methods that take arguments of
this type.

Make the class public instead of package-protected.

Add a test case.
INT-3148: Add MetadataStore Chapter

JIRA: https://jira.springsource.org/browse/INT-3148

* Add a general chapter about `MetadataStore`
* Add cross-links between chapters on the matter of `MetadataStore`

Doc Polishing
INT-3149: Cleanup of the What's New

JIRA: https://jira.springsource.org/browse/INT-3149

* Add a note about `GatewayMethodMetadata`
* Squash several sections to one by type
* Reorder by importance/interestingness
* Remove a note about `MessagingException` for `RetryAdvice`,
as the last one doesn't wrap exceptions to `MessagingException` on each retry
INT-2525 Add Connection as an HTTP Response Header

JIRA: https://jira.springsource.org/browse/INT-2525

INT-2525: Add test for 'Connection' header
[artifactory-release] Release version 3.0.0.RELEASE
[artifactory-release] Next development version
Merge remote-tracking branch 'upstream/master' into 4.0.0-WIP

Conflicts:
	build.gradle
	gradle.properties
	spring-integration-core/src/main/java/org/springframework/integration/config/RouterFactoryBean.java
	spring-integration-core/src/test/java/org/springframework/integration/channel/config/DispatchingChannelParserTests.java
	spring-integration-core/src/test/java/org/springframework/integration/gateway/GatewayProxyFactoryBeanTests.java
	spring-integration-core/src/test/java/org/springframework/integration/router/config/PayloadTypeRouterParserTests.java
	spring-integration-core/src/test/java/org/springframework/integration/transformer/MessageTransformingChannelInterceptorTests.java
	spring-integration-ip/src/test/java/org/springframework/integration/ip/tcp/connection/ConnectionFactoryShutDownTests.java
	spring-integration-ip/src/test/java/org/springframework/integration/ip/tcp/connection/TcpNioConnectionReadTests.java
	spring-integration-ip/src/test/java/org/springframework/integration/ip/udp/DatagramPacketSendingHandlerTests.java
	spring-integration-ip/src/test/java/org/springframework/integration/ip/udp/MultiClientTests.java
	spring-integration-ip/src/test/java/org/springframework/integration/ip/udp/UdpChannelAdapterTests.java
	spring-integration-jdbc/src/main/java/org/springframework/integration/jdbc/StoredProcMessageHandler.java
	spring-integration-jdbc/src/main/java/org/springframework/integration/jdbc/StoredProcOutboundGateway.java
	spring-integration-jdbc/src/main/java/org/springframework/integration/jdbc/StoredProcPollingChannelAdapter.java
	spring-integration-xmpp/src/main/java/org/springframework/integration/xmpp/core/AbstractXmppConnectionAwareEndpoint.java

Resolved.