INT-2900 Remove Extraneous Debug Log

When referencing a <gateway/> from a <service-activator/>, a debug
log is written with a full stack trace.

This is because all methods on the proxy are considered candidates,
but one method (addAdvice) has multiple parameters and can't be
used to process a message.

Add code to detect a proxy that has no target object; if the Proxy
only has one interface, then use that as the targetClass.
Merge pull request #733 from garyrussell/INT-2900

* INT-2900: Remove Extraneous Debug Log
INT-2906 Upgrade Groovy to 2.1.0
Merge pull request #746 from garyrussell/INT-2906

* garyrussell-INT-2906:
  INT-2906 Upgrade Groovy to 2.1.0
INT-2929 Fix JMX Occasional Failing Tests

ExponentialMovingAverageRateTests are VERY sensitive to
timing, when running on a busy platform.

Add code to skip the assertions if we detect we are
running on a slow machine.
Merge pull request #745 from garyrussell/INT-2929

* garyrussell-INT-2929:
  INT-2929 Fix JMX Occasional Failing Tests
INT-2853 ObjectToStringTransformer Improvements

* Convert byte[] and char[] to String rather than simply using toString().
* Allow the charset to be configured for byte[] payloads.
* Add tests.
* Add reference documentation updates.
Merge pull request #734 from garyrussell/INT-2853

* garyrussell-INT-2853:
  INT-2853 ObjectToStringTransformer Improvements
INT-2126 Add TcpConnection Event Publisher

Reference: https://jira.springsource.org/browse/INT-2126

* Add TcpConnectionEvent for OPEN, CLOSE, EXCEPTION.
* Add Event Type Enum - Provides type safety for event types.
* Add <int-ip:tcp-connection-event-inbound-channel-adapter />
* Add the ability to filter events (restrict to one or more subclasses)
* Add publishEvent() to TcpConnectionSupport to permit, for example, connection interceptors to publish events via the connection, but the event source can only be the connection used to publish the event.
* Add documentation to Reference Documentation section *What's New*

INT-2871 Provide Mechanism to Find TCP Connections
Reference: https://jira.springsource.org/browse/INT-2871

* Add getOpenConnectionIds() to Abstract Connection Factory
* Add closeConnection(String connectionID)
* Introduce removeClosedConnectionsAndReturnOpenConnectionIds

INT-2877 TCP Extension Improvements
Reference: https://jira.springsource.org/browse/INT-2877

* Make improvements to make extension easier.
* Add setCustomHeaders() to mapper.
* Add mapper to connection factory namespace parser.
* Add plumbing for stateful Deserializers.
* Refactor setting standard headers
* rename setCustomHeaders to supplyCustomHeaders - returning a Map and not exposing the MessageBuilder to subclasses

INT-2872 Remove Deprecated Items in ip Module
Reference: https://jira.springsource.org/browse/INT-2872

* pool-size Attribute
* setScheduler
* TcpSendingMessageHandler.getConnection()
* Deprecated attribute on TCP Connection Factory.
Merge pull request #743 from garyrussell/INT-2877

* garyrussell-INT-2877:
  INT-2126 Add TcpConnection Event Publisher
INT-2931 Fix Router Race Condition

AbstractMessageRouter.getRequiredConversionService() and
IntegrationObjectSupport.getConversionService() try to initialize the
conversion service and may be called from multiple threads. There is
a race condition where this could end up in an uninitialized conversion service
causing NPEs in subsequent method calls.

To solve this issue, the conversion service is initialized with
double-checked locking.

For further details see https://jira.springsource.org/browse/INT-2931

INT-2931 Polishing - Add Test Case

Add a test case that reliably reproduces the issue and verifies
the fix.
Merge pull request #747 from ferstl/INT-2931