Currently all messages are broadcast to all clients. I think this patch prevents a client's own commands from being sent back to them. Currently completely untested because I don't know how. Do we have a procedure for testing network code?
Built on top of D4773 so the code makes sense to read. Changes are at NetServer.cpp:402 and NetClientTurnManager.cpp:54.
Reduces command traffic by a ratio of 1/(number_of_players + 1).