Catch cryptlib version mismatch gracefully

No functional change.

The wrong version nubmer was specified for these new properties - these
properties were added in v3.20c which is represented numerically as 32002 in
decimal.

The description of the tls_psk_id property was missing socket_prop_desc.

There are now two ways to authenticate with the broker:
1) TLS PSK with a sysop account, and set the password field at the
   MQTT level to the system password (user field, if present is
   ignored).  This is the prefered method as it provides mutual
   authentication and you simply can't steal credentials with MITM.
2) Synchronet TLS certificate, sysop username and the users password
   followed by a colon, followed by the system password.  The server
   authentication will now depend on the appropriate trust chain in
   the client.  If using a Let's Encrypt certificate for example,
   you can' securely connect to localhost with this method.

tools and libraries tend to allow TLS-PSK with password at the MQTT
level, many GUI tools do not allow TLS-PSK.

Now both the "regular" certificate, and PSK will be supported on
a TLS socket, and it's up to the client to check which was used.

trimmed some trailing whitespace

of an existing one.

If tls_psk is used, indicates which entry in tls_psk was used by
the remote.

Broken with the paranoid_strtoul() addition

As much as possible, ENTER should mean "no change".

A sysop can do the same by going through the 'I' (user config/settings
command), but that's a bit more convoluted.

Since it's technically a "local post", but the user/sysop wants their client-
provided email address to appear in the header, use it, if provided (don't use
a made-up BBS email address that may not be valid).

For Accession

With this, you don't need a username, password, PSK, or PSK ID,
certs, CAs, etc, and things just work by magic (when using the
Synchronet broker)

For when running as a service.

As always when writing documentation, fix things that aren't quite
right... we now schedule nextPacket, but run each packet to
completion as long as we have all the bytes.

We don't need this anymore because the paranoid wrapper does it.

This is kind of a prototype for xpdev... but it's a bit klunky.

The issue these fix is that some C libraries (Windows and GLibC)
will return 0 and leave errno unset when no digits are converted,
while other libraries (FreeBSD and musl) will set errno if no
digits are converted.  This means that even setting errno to zero
before calling, then checking it if the return value is zero is
not enough to catch errors.

This actually led to Windows and (most) Linux systems not being able
to download the web lists because of a bug where it was converting
starting in the middle of the string rather than where the numbers
are.  It worked fine on Alpine Linux and FreeBSD though.

content-length: and content-transfer-encoding: were badly broken.

I'm totally perplexed that none of the compilers we have warned about this
obvious incorrect usage of the toggle_flag() function. Not warning about
passing false (0/NULL) for a char* makes some sense, but not the passing of
a const char* in place of a bool (int)? Maybe we should be building with
-Wall?

Thanks Microsoft!

If we called accept(), it's not datagram, and if you're using SCTP
and Synchronet lies to you, you can fix it yourself.

For use by broker.js which now requires a Sysop User ID and password
as the TLS PSK, and requires the system password in the MQTT password
field.

Because of the way this script is invoked from str_cmds.js (using js.exec)
any exceptions were just silent failures, making debugging issues
(e.g. the recent regression with the global ascii() function) difficult.

vert.synchro.net is taking > 15 seconds after initial IRC version notice

As Nelgin pointed out, there are a few hard-coded strings in the C++ source
with attribute (Ctrl-A) codes still.

This commit takes care of 5 of them:
- TelnetGatewayPrompt
- QWKEndOfMessage
- QWKTagLineFmt
- QWKControlCommand
- QWKBadControlCommand

Yes, you can do the same thing with timed events, pretty much

Embarassingly, I'd added SS_NEW_DAY recently (for a different purpose) with
such a similiar name. So let's rename this flag since it serves a very
different purpose and avoid the confusion between the two flags.

This hasn't done anything SBBSv3 - no way to enter internal user editor
recursively.

When passed null or undefined, it needs to return null or undefined.

Document that behavior.

It's CryptCert.FORMAT.XXX