network: when closing a socket in the SYN_SENT state, send an RST and move into the CLOSED state, rather than complaining about an invalid state for close.
network: handle out-of-order segments in TCP better (send an ACK with the sequence we expected)
network: set default TCP MSS to 1460 and advertise in all new connections - needs to be dynamically selected...
network: in TCP, don't send a FIN in anything other than the CLOSE_WAIT or ESTABLISHED states