POE component base class which implements the Observer pattern

 POE::Component::Syndicator is a base class for POE components which need to
 handle a persistent resource (e.g. a connection to an IRC server) for one or
 more sessions in an extendable way.
 .
 POE::Component::Syndicator (as well as Object::Pluggable, which this module
 inherits from) was born out of POE::Component::IRC, the guts of which quickly
 spread to other POE components. Now they can all inherit from this module
 instead.