Merge pull request #777 from garyrussell/INT-2970

* garyrussell-INT-2970:
  INT-2970 Update to Spring-AMQP 1.2.0.M1
INT-2939 LoggingHandler Improvements

- Don't evaluate expression if the log level is not enabled
- Add mutually exclusive assertions (already protected by the parser
  but not for programmatic configuration).

INT-2944 Document <logging-channel-adapter/>

Add reference sub-chapter.

INT-2939 Polishing - PR Comments

- remove unnecessary cast.
- add setter for level changes.

Polishing

* Change setter to use enum.
* Add getter for current level.
* Rename method to 'createLogMessage'.
INT-2939 Polishing

Add assert for non-null Level.
Merge pull request #754 from garyrussell/INT-2939

* garyrussell-INT-2939:
  INT-2939 Polishing
  INT-2939 LoggingHandler Improvements
INT-2956 Fix NIO With Custom Deserializers

The TcpNioConnection uses an internal InputStream.

The standard deserializers only use the read() method.

Custom Deserializers might use read(byte[]); the
internal InputStream did not override these methods, possibly
causing the deserializer to hang awaiting data, when none
was coming.

Override these methods, with the appropriate semantics
from the super class...

- Block until at least one byte arrives.
- Return early if no data is available after at least one byte arrives.
- Return -1 if closed when no data arrived.
- Return the number of bytes actually read.

Polishing - PR Comments remove read(byte[]) because it doesn't do
anything different to the superclass method.