JSDOC fix-ups.

Mostly just bitfield->bit-flags.

A little more visiblity into the MQTT library (version, function return values)

Recently started truncating trailing whitespace from sender/recipient names
before calculating the CRC value (similar to what we do for message subjects
as of a year ago). To suppress errors when evaluating messages (with trailing
whitespace in sender or recipient namems) created or imported before this
change, use this new -N option.

And don't offset long(er) windows from edges to allow more options to be
on screen at once.

Tested with 50 column mode.

Fixes Windows build.

Right now, only supports publish, subscribe to come next.

Only included with the mosquitto lib support is enabled in the build.

No functional change, just a little clean-up.

ftouch(), semfile_signal(), and JS file_utime() would fail to update a file's access/mod times with errno=EPERM if not run as the file's owner. From "man utime":

EPERM times is not NULL, the caller's effective UID does not match the owner of the file, and the caller is not privileged (Linux: does not have the CAP_FOWNER capability).

So use a NULL times parameter value when updating to a file's time stamp(s) to the current time.

One of the benefits of the new .ini format config files. :-)

This increase introduced a few potential buffer overrun warnings (all writes
to smb_t.file ?)

... using snprintf() instead of sprintf()

Since we are now free()ing the opt[] items in bail(), I've seen heap
corruption core dumps after navigating the SCFG menus with some long
configuration items (e.g. timed events with max-length command-lines).
This heap corruption has been present for a long, long time, but not
detected since we weren't free()ing these heap-allocated items.
Increasing MAX_OPLN would have been a mitigation for this issue, but
using snprintf(opt[n],MAX_OPLN,...) is the better fix.

Copy/pasted (with little modification) from
https://synchro.net/docs/file_section.html#AdvancedOptions -> "Short Name:"

Some short names have specially predefined meaning and it's important to
include that detail here.

Unlike strip_ctrl(), does not remove any other control characters from string.

the Subject CRC calculation was changed in May of 2022 (trailing whitespace is
removed prior to calculation), so messages imported before this date/revision
of sbbs might be detected as having an invalid/mismatch Subject CRC. This -S
option can be used to suppress such errors (for Keyop).

Don't support /option syntax any longer in non-*nix builds (just -options).
Options are now case-sensitive (i.e. -S and -s are different options).
Bump version to 3.20.

As Deon pointed out:

I saw that smbactive was removed recently (719b7523), but a quick search of
code, sees reminants in GNUmakefile and other files, which I'm wondering is a
cause of the problem...?

... rather than just failing silently with a special return value
(e.g. false).

When sending a user-to-user file transfer, SBBS (since v3.19) will check that
the file recipient will be able to download it (e.g. doesn't have restrictions
preventing it) and this was failing for most (non-sysop) recipient users since
they wouldn't normally meet the "access restrictions" of the user directory
(by design).

So use js_argc() to report an error if there's fewer than 1 argument, but
don't just fail silently when 2 arguments are provided.

Avoids crash when adding a msg to a non-sub-board msgbase.

It's possible to use savemsg() (from JS MsgBase.save_msg()) to add a message
to a message base that's not a sub-board (not configured in SCFG->Message
Areas and not the "mail" base), but in that case, savemsg() would dereference
an invalid sub in the scfg->sub array and crash. So use is_valid_subum()
to insure the subnum is a valid sub before using as an index.

If/when anyone wants this functionality again, write a short JS util.
For reference:
https://synchro.net/docs/utility_reference.html#SMBACTIV

This fixes issue #384.

This should resolve CID 453850

My first idea was to have a per-external-program setting to enable input
translation, but Deuce suggested it would be better done in input_thread() and
after some thought, I agree. Translations are not done in data/file transfer
mode, so use the CON_RAW_IN console flag to indicate this condition. So even
JS console.getbyte() will return a translated char unless the console is set
raw input mode (this could be surprising behavior for some!).

I considered saving/restoring the console mode when performing a file transfer
but will leave that to a time when obviously needed.

This fixes issue #497 in automatic way (no option needed).

e.g. when using Ctrl-K or when being prompted for key-press due to inactivity

A bare '\r' doesn't move the cursor to the first column in PETSCII terminals.
The '[' Ctrl-A code moves the cursor to the first column with multiple
cursor-left sequences, if necessary.

Ideally this sequence would be part of the text.dat string instead of
hard-coded here.

This fixes issue #561

jsexec is an extra weird case though, so don't touch that one for
now... I assume it'll just break as-is, but maybe it'll work...
Certainly gdi_ciolibinit() needs better error detection.