Change default queue names to role/port [BREAKING]

This matches common conventions in MQTT and other systems
better, using / to denote hierarchies of topics/queues.
If the old convention is needed, explicity specify 'queue'
as part of Participant defintition

Author: jonnor

msgflo/msgflo.py

@@ -34,7 +34,7 @@
 import paho.mqtt.client as mqtt
 
 def addDefaultQueue(p, role):
-  defaultQueue = '%s.%s' % (role, p['id'].upper())
+  defaultQueue = '%s/%s' % (role, p['id'])
   p.setdefault('queue', defaultQueue)
   return p