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

TcpConnectionEvent for OPEN, CLOSE, EXCEPTION.

<int-ip:tcp-event-inbound-channel-adapter />
INT-2871 Provide Mechanism to Find TCP Connections

https://jira.springsource.org/browse/INT-2871

Add getOpenConnectionIds() to Abstract Connection Factory

Also add closeConnection(String connectionID)
INT-2877 TCP Extension Improvements

Improvements to make extension easier.

* Add setCustomHeaders() to mapper.
* Add mapper to connection factory namespace parser.
* Add plumbing for stateful Deserializers.
INT-2872 Remove Deprecated Items in ip Module

- pool-size Attribute
- setScheduler
- TcpSendingMessageHandler.getConnection()

Deprecated attribute on TCP Connection Factory.
INT-2126 Add Event Type Enum

Provides type safety for event types.
INT-2871/2877 Polishing - PR Comments

* INT-2871
** Revert harvestClosedConnections to return void
** Introduce removeClosedConnectionsAndReturnOpenConnectionIds

* INT-2877
** refactor setting standard headers and move back to toMessage
** rename setCustomHeaders to supplyCustomHeaders - returning
    a Map and not exposing the MessageBuilder to subclasses
INT-2126 Polishing - PR Comments and More

PR Comments:
* Rename event adapter to tcp-connection-event-inbound-channel-adapter
* Add the ability to filter events (restrict to one or more subclasses)

Also:
* 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.
INT-2126 More PR Comments

Fix type in Event iteration.
INT-2126 Polishing; Schema; What's New