debug log msg.

more (!) by removing the sections from the total file string list, once parsed.
Fixed a couple of minor and unlikely off-by-one errors with message ptrs
based on date/time.

option - the sysop chat availability is now controlled via semaphore
file (ctrl/sysavail.chat).

via BBS/terminal server startup option flags, now controlled via semfile).

each section (sub-code) once. Should cut the search/parse algorithm by 66%
(since there's 3 keys/values we're searching for, per sub).

users) and adjusting scan ptrs by date or set to "Last msg" while online:
- speed (on my system, reduced from 12 to < 2 seconds)
  This involved 2 enhancements: check msgbase index file timestamp (fast)
  before opening any files. When opening the msgbase, just open the index
  file (no other msgbase files) - required new smblib function: smb_open_index.
- fixed off-by-one when setting by date (when setting the new-scan ptr to
  Jan-1-2018, you want that first message posted on/after Jan-1-2018 to be
  found as "new", not the first message posted *after* that date.
- re-added the fixmsgptrs() call in putmsgptrs(), inadvertently removed
  in the .ixb -> .ini ptr storage update in rev 1.192 of userdat.c.

Most of the copyright years in the source code were misleading (the date of
most recent publish was actually later) and all were unnecessary. I've been
removing copyright years piecemeal, for a long time, but I decided it was time
to just perform a bulk search and (mostly) replace. In some cases, I left
old copyright years on files that either are not used (and soon to be removed)
or obsolete and unlikely to ever be touched again (e.g. Win9x FOSSIL VXD). Some
of the runtime binaries still contain copyright years and those were updated to
2018.

output. Example:
File size        : 7,128,414 (6.8M) bytes

the number of decimal places in the resulting string.

matches the search spec, the 'D' batch-flagging command would invoke the
downloadfile() method which confusingly, doesn't actually download (send)
the file, but instead performs all the post-download functions needed. So
the user would just see "<filename> sent." and possibly lose some credits
without actually receiving the file.

Created byte_estimate_to_str(), much like byte_count_to_str(), except the
byte count is rounded to the nearest tera/giga/mega/kilo-byte
(technically tebi/gibi/mebi/kibi-byte, but ugh, I'm old-sk00l!).

The "official" log line format is (as of right now at least):
"[socket] [protocol] [user/host-ID] [! if error]message"
Hopefully I can remember that when I add new log messages.

Also setting the protocol to SMTPS, POP3S, SEND/TLS, when appropriate and
passing it around to pretty much any function that can log a message.
Added debug-level log output when the mail sever is sending message body text
(every 100 lines).

The "max lines" parameter value passed to sockmsgtxt was using the cryptlib
session number - this would truncate sent email bodies to some seemingly
random number of lines. Introduced in rev 1.622.
Also added a couple of helpful log lines to let the log-reader know if/when
TLS was successfully negotiated for sendmail sessions.

(defaults to 10 megabytes, "10M").
When SBBSecho starts up, if this minimum amount of free space is not
available in any of the following directories, SBBSecho will display an
error and immediately exit:
- data directory (in SCFG)
- logs directory (in SCFG)
- netmail directory (in SCFG)
- outbound directory (from sbbsecho.ini)
- temp directory
- each linked-node's outbox, if configured

If the sysop runs out of disk space for some reason, at least SBBSecho
won't contribute to the problem.

Version 1.17 beta 63: Just before showing the message list or changing to another message area from the reader interface, it now writes "Loading..." in case there are a very large number of messages or sub-boards.

so remove 'errno' value (and corresponding error strings) from generated
/logged error messages. fseek(), read(), write(), open(), etc. do set errno
to a meaningful value, so we still log errno/strerror() in those failure
cases.

prompts with the conditional beep enabled only with the '-b' option
(silent by default). Thanks to Nelgin.

with smb_t.status.

log prefix solution.

can return false on error, which is >= 0, so this will just add 0 to the
length and keep on looping forever in that case.

not null on failure.

Also, is that some line ending weirdness?  *shrug*

'l' (list messages), 'x' (dump index), 'r' (read msgs), and 'v' (view msgs)
commands by "days old", by specifying a negative number (in days).
(e.g. "smbutil r-30" would read messages posted within the past 30 days).
This was added to test the smb_getmsgidx_by_time() function, but has some
value otherwise I suppose.

recvFrame() is being called in a loop and only breaking on specific
conditions or if recvFrame returned undefined. Problem is, on timeout,
recvFrame returns null (and when using === comparision, undefined !== null).
Also added more debug output around sends where I suspect there might be
another potential infinite loop.