Added some multiplayer code to the server
Players are being added in the client

The client sends a debug player to the server, with a constant movement to
show that the new client _is_ connecting. The next thing to add is the
sync system, so that the clients know what the server looks like when they
first join.
Fixed for loops using the auto keyword
Synchronization works
Simplified the packet system
Deleting players on logout
Simple Multiplayer is working