Fix debug message in DCAware policy.
Ensure connections are cleaned up when pool construction fails.
Ensure channel gets closed when Connection construction fails.
Ensure failed control connection attempts always get closed.
Free reference to Channel when closing connection.
Ensure updateCreatedPools does not add pools for suspected hosts (JAVA-593).

The check in replacePool is not part of the fix, but it was added
as a security measure since it was where connections were leaked.