AMQP-337 Emit Closed Event on All Closes

Previously the ConnectionListener.onClose() was only called
when the connection factory was destroyed, and not when a
closed connection is refreshed.

Also, the onClose() in destroy passed in the target connection
instead of the proxy (which is what is passed to onOpen().

JIRA: https://jira.springsource.org/browse/AMQP-337