TCP/IP based multiplayer games

This specification aims to improve and extend YR's multiplayer capabilities by allowing the game to use TCP/IP for LAN games, instead of the IPX/SPX protocol currently used, which is not available in post-XP Windows.
The code should be written in a way that is not actually limited to LANs, that is, it should allow direct-connection multiplayer games over the Internet, without requiring XWIS.