Add RdNetworkManager to deal with network connections
Merge remote-tracking branch 'origin/simpleApproach' into network
RdNetworkManager now does login, logout and hit
Update client program to use the RdNetworkManager
RdMentalMap is updated automatically on data arrival
RdNetworkManager now sends updates automatically

RdMentalMap notifies to its listeners when a player is hit, so
that RdNetworkManager can send the notification to the server