Based on SocketMUD 2.4

Changes:

Removed threading and the dns lookup (which arguably don't have much use) and some other changes to get the code to compile cleanly on Cygwin.

Removed the old mccp code and added MTH (Mud Telopt Handler) instead which adds NAWS, TTYPE, MCCP, MSDP, and MSSP support.

Added local echo handling for passwords.