Config provides host_and_ports Stomp parameter

A default connection uses it.
Update fixture: Stomp connector doesn't need sec.
Config connector independent user/password lookup
StompConnector.default_connection is a classmethod

Instead of a staticmethod, so I can override it with ease.
Simple action send reply-to header: 2.3.x required
Add RabbitMQ connector
Move connectors common to BaseConnector class

Instead of being implemented by StompConnector