Expose setting loppback multicast packets in constructor.
Update Application and Neighbourhood due to changes in UdpMulticastSocket.
Micro clean up in UdpMulticastSocket.
Update UdpMulticastSocket test.
Fix Serializer test.
Yet another redesign of Serializer  interface.
Introduce protocol.hpp describing packets exchanged over network.
Fix InputOutputBuffers interface (broken methods protection level classification).
Update protocol.hpp and add some comments.
Implement Neighbourhood::announce_presence().