This should bit by bit substitute RsNotify which would be very difficult
to support properly in JSON API.
The new system is much simpler to use also from the C++ side of the
moon.
BroadcastDiscovery take advantage of the new system to notify about new
non friend peer discovered, tested successfully also in JSON API.
Discover peers on the same broadcast domain/LAN
Implements own node announcement
Implements others announcement listening
Implements API to get notifiend when other nodes get discovered
Implements API to get discovered nodes
Add discovered peer locator to rsPeers if it is already friend
Yet a bunch of things to do to take full advantage of this new
implementation
