was printing the filename in uppercase if configured as such

Rather than a single file with config for all subs, use a separate
file for each sub.  This makes clients that do parallel connections
to different mailboxes work much better, and make loading and saving
the config for a mailbox much faster.

The caching stuff is removed to simplify things, and hopefully won't
need to come back... we should just not save config if it doesn't
change.

Only issue I'm still aware of is that 99% of IMAP clients just can't
deal with slashes in mailbox paths.  Like... at all.  The protocol
supports them, but every client seems to have a different way of
breaking with them.

No sense downloading articles we're just going to toss out the next time
we performance msgbase maintenance.

... which simplifies the fmutex_close() function and signature.

By default, the duration is infinite, but some sysops may not want this
file to be ever-grower but rather periodically pruned by the new trashman
utility.

Sysop that don't use spambait.cfg won't benefit from this change.

Also, don't get hostname unless we're surely going to write to the file.

The 'atomic_remove' argument isn't used in non-Windows builds since we can
remove() before close() on non-Windows OSes already.

I managed to hit a bug where bseen and seen were both completely
filled.  No idea how I hit it, so not positive it's fixed.

This is cheap insurance against the 43k file groung to 1.6MB for
someone else.

1) Cache the binified seen data rather than regenerate every time
2) Only call js.gc() after a complete fetch or store loop

O_EXCL doesn't appear to be working very reliably over Samba, so let's add
file locking to the equation.

glob() results might be out of date by the time we look at each file, just
skip missing QWK pack semaphore files silently. This should resolve the
".now already gone" messages too. Hopefully.

Removed some extraneous quotes around logged event command-lines.

Also when detecting a blocked event_thread, log the event_code that is/was
running last.

Should be no functional change.

Also, make save_cfg() require that the lock be held.

This should now actually work properly.
Also, add a debug_exceptions flag to rethrow exceptions so I can
get line numbers.

It shouldn't though.

Also, always use full_send(), not the socket send.

This removes unnecessary some cruft and complexity, most especially from the
event_thread().

Using sbbs_t::fremove() instead of remove(). This probably resolves some
Coverity issues where we weren't checking the return value.

ENOENT = "No such file or directory"

Passing 'true' for the optional 'log_all_errors' parameter overrides this
(logs all errors, including ENOENT).

Only log message header read error if the msgbase.status is non-zero

Don't try to import anything if the stop semfile is signaled while
exporting.

Increment revision to 1.2

Add log message when spawning background timed event

Only log messages about QWK mutex files existing when > 60 seconds old

First, fix the logged username bug in the "Lock exists" log message.
Next, double check that the trigger file (sem file or REP file) still exists
after acquiring the file mutex.

Use a temp varible (fname) to make the code easier to read.

Also, after grabbing a lock, enter a try/catch that will unlock
and re-throw the error.

Vertrauen's FTP server gets abused by QWKnet logins sometimes and handling
the race conditions around QWK packet creation attempts is silly - there's
no legit reason why a QWKnet account needs to be logged-in multiple times
concurrently to the hub's FTP server, so reject the subsequent logins even
when they're on different hosts (as is the case with Vertrauen).

As part of this change:
- fmutex() now takes an new time_t* argument to (optionally) store the
  time of the mutex file for helping logging (locked since when?).
- time_as_hhmm() created to format a string as either HH:MM or HH:MM[a|p]
  (depending on system configuration for 12 or 24 hour time formatting).
- renamed the old hhmmtostr ()to tm_as_hhmm() (since it takes a struct tm arg)
  and have it return a non-padded string (useful in more situations without
  requiring truncation) when the sysop prefers 24-hour time.

Pretty remedial option parsing here, the order is significant