Let there be TELNET

[larsbrinkhoff]

I like to post premature pull requests, so here's a draft. You can never have enough TELNET.

This should resolve #1306 (UT - user telnet) and #1269 (TN6 - "Multics/Moon's" telnet). Both programs .INSRTs the host table, so that file is added too.

EDIT: Now also #1310 (STELNT - server telnet).

[larsbrinkhoff]

I saw a line in TELSER: .SUSET [.SXJNAME,,[SIXBIT/TELSER/]] ;TELNET SERVER - THIS IS FOR STLGET TO WIN. I never saw it before, but apparently ITS has this call.

STLGET: get information from Server Telnet

        arg 1   a <TTY>

        val 1   XJNAME of server telnet
        val 2   TRMNAM of server telnet
                This is the sixbit name of the host connected to.
        val 3   SNAME of server telnet
        val 4   In LH: STY status bits
                In RH: index of telnet server job which owns the STY.

        This call can be used to find out where in the network
        a TTY really is.

        The STY status bits are from the STYSTS table in ITS.
        Some of the more interesting ones include:
        %SSNET==4000    ;4.3 = 1 => THIS STY CONNECTED TO SOME NET SOCKETS.
        %SSCHA==2000    ;4.2 = 0 FOR ARPANET, 1 FOR CHAOS NET
        %SSTCP==1000    ;4.1 = 1 for TCP internet (%SSCHA must be 0)