Extension points for clients

Change-Id: Ib4d1d45bde7bd8b0edc224d84c75dafd15b6f455
Removed matchmaker stuff

Change-Id: I3750c0984cbd891dbfbb033d48e76d79916eb328
Simple ZMQ Notifier

Performance test results in P2P mode:
Notifier - 50K m/s
NotifyListener(eventlet) - 25K m/s
NotifyListener(blocking) - 45K m/s

TODO implement proper addressing and topic matching

Change-Id: Ida45e1fcfb7fc488ca4b2111701c80518831a483