[Multiplayer] Many-player considerations

[akarnokd]

This issue is deliberately locked down.

• [x] How to run more than 2 copies of the game without massive slowdowns for all instances or BSODs.
• [x] How to distinguish between logs coming from client 1, 2, 3 etc. on the same machine.
• [ ] How to access the inventory of offline clients.
• [x] How to distinguish inventories of client 1, 2, 3 etc.
• [x] Show client user names on the UI in some fashion.
• [ ] Client icons next to the user names.
• [x] Allow client 1, 2, 3 etc. color customization on the avatar.
• [ ] How to configure multiple clients on the same machine.
• [x] Client names above the avatar.
• [ ] Kick and/or block clients.
• [ ] Shredder use restrictions.
• [ ] Deconstruct restrictions.

[akarnokd]

Multiplayer mod is now discontinued.