INT 15 U - DESQview v2.50+ - GET/SET SOCKET HANDLER
        AX = DE2Dh
        CX = direction
            FFFFh set socket handler
                DX:BX -> FAR function for socket interface
                        must be of the format described under INT 63"DESQview"
            other get socket handler
                Return: DX:BX -> socket handler
Notes:  DESQview 2.50-2.52 are distributed as part of DESQview/X v1.0x.
        the "set" subfunction is normally called only by SOCKET.DVR
SeeAlso: INT 63"DESQview"