INT 7A - Novell NetWare - IPX Driver - CLOSE SOCKET

	BX = 0001h
	DX = socket number (high byte in DL) (see #03809)
Notes:	also cancels events set by any Event Control Blocks for the socket
	the program must close all open sockets before terminating
	this function is supported by Advanced NetWare 1.02+
	When the NetWare-specific release of the DR DOS command processor does
	  a NetWare shutdown sequence on exit, it will close all user sockets
	  except for socket numbers 4000 and 4001, which seem to be used by IPX
	  internally.
SeeAlso: BX=0000h