Merge pull request #2 from mtharp/master

Two error handling fixes
Fix unremovable listener

When connection is renewed, listener for previous connection is not
removed from the list of listeners in RMQConnection.

This patch prevents such situation.

The same logic as ConsumeRMQChannel#OnCloseCompleted().
Fix clear timing

If clear some members before listener's method is invoked, it cannot
refer them correctly.

This patch delays clear timing.
Add information to some log messages
Add information for test
Replace Logger from sf4j to java logging
Refine log messages
Refactor shutdown logic

* Log if connection is suddenly disconnected
* Log if channel is suddenly closed
* RMQManager: Clear RMQConnection instance just after invoking close().
  * Revived patch. Thanks @mtharp !!