MessageDirector: Add helper function MDParticipantInterface::send
MessageDirector: Rename MessageDirector::InitializeMD to init_network
Network: Add NetworkClient and switch MDNetworkParticipant to use it.
MessageDirector: Convert MD to use NetworkClient
MessageDirector: Moves control message handling to MDNetworkParticipant
MessageDirector: Moves m_range_susbcriptions initialization to ctor
Merge pull request #45 from OpenOTP/mmavipc

Refactor MD