SubscriptionListeners and Authorizers should not extend CometD interfaces

[uklance]

org.lazan.t5.cometd.services.Authorizers currently extends org.cometd.bayeux.server.Authorizer

org.lazan.t5.cometd.services.SubscriptionListeners currently extends org.cometd.bayeux.server.BayeuxServer.SubscriptionListener

these should be POJO interfaces, this might require the use of anonymous inner classes in CometdModule