This is used by some BBSs to enable encryption without needing to
integrate the BBS user base into their SSH server (and presumably
so they don't need to run multiple SSH servers).  All users log in
with the same username (ie: "bbs") and no password is requested or
required.

Once the BBS starts, it prompts for the BBS user name and password
as normal.

In SyncTERM, the user/password/syspass fields are redefined as
SSHuser/BBSuser/BBSpassword and they are moved around when you
change the connection type.  This means that if you change a listing
that has a syspass to SSH (no auth) and back, the syspass is lost.

I'm not sure if I plan to fix this or not.

It's not clear if this is working properly or not since the only
BBS I know of that supports telnets (fido.beholderbbs.org) doesn't
seem to do any telnet "stuff".

Should fix SF #45 since it appears the input thread started then
exited before SyncTERM realized the connection was successful.

In preperation for telnets support, make conn support TX/RX parsers.
Make telnet use those new hooks, and remove unused and ambiguous bits
of the conn API (conn_recv(), conn_peek()).

There are a number of conio changes in here too... too many to list.  Check
the diffs if you actually want to know what changed.

sourceforge.
https://sourceforge.net/p/syncterm/feature-requests/13/
This also addresses request 14
https://sourceforge.net/p/syncterm/feature-requests/14/
And disables uifc during startup.

casting to the preferred type inside the function.

shell connection on Windows to corrupt the entry.  Instead, add a generic
failure for any unsupported connection (including compile-time disabled
methods).

Fix settings like "RLogin Reversed" and "C128 (80col)" in enums.  Enum
values can't have spaces in them.

that's what Windows does when a non-blocking connect() fails.

Should fix the IPv6 localhost issue.

Exit the connect wait loop if the socket is set invalid.

Add -4 and -6 command-line arguments.
Add csr capability to built-in terminfo.

defined on that platform.

Fixes crash on OS X (and double-free everywhere else) after a getaddrinfo()
succeeds, but the connect fails after returning EWOULDBLOCK/EAGAIN/etc.

Reported by Michael Montague (thanks!)

or potentially more with a timeout to at least one byte.

Does not disable SSH options in menus, just makes the binary NEVER work
with Cryptlib.

prompts to read "Device Name" when in Serial connection mode.

Prevents hanging on DCD.

Follows DSR rather than DCD and DTR is de-asserted at the end of the
input thread rather than by mode_close()

May still have issues with modem_close() if DCD is still asserted (unlikely)