Reported by Max (WESTLINE)...

Introduced in commit 75c5c9e5, since we are now calling the set_state()
callback periodically, and in sbbsctrl, it sets/resets the pause button
checked (depressed) state in response to this callback (should it?), this was
resetting the pause button checked/depressed state peridically (at the
configured sem file check interval, default 2 seconds).

The fix: if the new server state is the same as the previously set server
state, don't call the set_state() callback. I considered this as a potential
optimization when I first wrote that commit, but didn't see any obvious
downside to calling the set_state() callback redundantly. Now that I see a
downside, let's implement this saving/checking of the state to avoid
redundant "set" calls.

... with a socket descriptor value of -1.

The 5th character must be a digit.

Prevent future stupidity such as happened with recently added and then
fixed NODE_USER @-code.

Since "NODE*" is a match for a node number status (ugh), and this comparison
happened before the comparison for "NODE_USER", we'd never hit that condition.
Thought I tested this before original commit, but I guess I did not. Oops.

This recent enhancement (Commit 61a3ab2d) introduced security and usability
concerns.

So I created (and am now using where requested) a wrapper for formatting
text.dat/ini strings which will automaticlaly detect @-code encoded strings
and expand/use them *only* (instead of printf %-specifiers).

This might impact issue #696 since although unintentionally, it actually was
possible to mix @-codes and %-specifier usage in certain (node status)
text.dat/ini strings, but that should not be possible now. It's either/or:
@-codes or %-specifiers, not both.

Needed for exactly reproducing built-in node status string formatting using
@-codes (only).

Note: format specifiers (e.g. %s) cannot be combined with @-codes (use one or
the other, not both).

Fixes issue #696

If you need additional text strings to support @-codes, you'll have to specify
them explicitly in feature request issues.

We have checks/loops/timeouts waiting for active clients to disconnect and
child thread threads to terminate whenever shutting down or recycling already,
so this should be safe. This pretty simple change fixes issue #236 (can't
terminate server under heavy load).

Also as part of this commit, introduced the ability to "pause" a server
(prevent it from accepting new connections) with the ctrl/pause semaphore
file or via the MQTT server/pause (and resume) topics. This feature is useful
when debugging server issues where you don't necessarily want to fully
shutdown/terminate the server, but don't want any new connections to be
accepted (the listen backlog will fill up with incoming connections though).
Unlike a server shutdown, a server pause can be "undone" via MQTT (by
publishing a message to the "resume" topic).

The "pause" semaphore file is just an "existence" semaphore file - its
date/time stamp doesn't matter. If the file exists, the server will enter
a paused state (and periodically log messages to that fact) until the semfile
is deleted.

This server pause feature is not the same as the pause button function in
sbbsctrl, which just pauses server log output.

that doesn't log an error

Support was accidentally removed as part of commit 22e8d2e3, meaning
the ftpalias.cfg wasn't used at all in responses to the MLSx commands as
reported by Max (WESTLINE) using Total Commander, FileZilla and Directory
opus. The traditional "LIST" commands still worked fine with ftpalias.cfg
contents just fine.

The reason this code was accidentally removed was due to the errant
copy/pasted comparison with startup->html_index_file that did not belong here
and made the block appear related to HTML index file generation. It was not.
This was just a bug in the initial implementation of MLSx support in
commit d4deb4b3.

Also included in this commit:
- Return the date/size of the user's QWK packet file, if it exists, in MLSx
  response.
- send_mlsx_entry() won't report negative time_t values as file modify dates
 (flength returns -1 upon failure/file-not-found).
- get_owner_name() returns the string, making it easier to use in function
  calls.

There appears to still be some work to do to make the MLSx commands fully
compliant with RFC 3659 (e.g. "mlst filename" from ftpalias.cfg should work
but does not), but at least FileZilla displays ftpalias.cfg files and
directories correctly now.

Reusing the variable 'str' here for multiple purposes meant the QWK packet
filename was overwritten by the owner name (the system's BBS-ID):

 ftp> mlsd
 229 Entering Extended Passive Mode (|||2001|)
 150 Opening ASCII mode data connection for MLSD.
 Type=file;Perm=r;UNIX.ownername=VERT; 00index
 Type=cdir;Perm=elc;UNIX.ownername=VERT; /
 Type=file;Perm=r;UNIX.ownername=VERT; VERT

That last file there should have been "VERT.qwk"

Since lock_ssl_cert() is a reader lock, there shouldn't be a whole
lot of contention on aquiring it anyway, and we can thundering herd
our way out of it when it clears.

without locking!  That's chaos!

This ancient bit of was re-writing node.ini files needlessly

Expanded to CRLF or just CR (if strip LFs is enabled).

It is possible for someone to stuff LF-terminated text in a message, so let's
account for that possibility upon export to FTNs where LFs are supposed to be
ignored.

Hopefully help debug why HTTPS isn't working for him

This partially reverts commit 7d26ad80 where a bunch of read() and write()
return value checking was added.

The proper sentinel value here for "no TLS session" is -1, not 0.

This, at minimum, was causing a lot of extraneous calls to destroy_session()
(from js_socket.c's do_js_close()) with an invalid (hopefully, not
otherwise used) cryptlib session ID of 0.

Nothing checks or logs the return value of destroy_session(), but I'd expect
it to be failing ... a lot.

This was broken one year ago in Commit e631451e

Thanks for the report (just now) about this bug Max!

The year is 4 digits, so the offsets aren't the same as the other 2 supported
formats. Doh!

Thanks Max for testing!

... using WIN_FIXEDHEIGHT mode to limit the list height in wizard mode.

I had a solution using a negative width param value to specify a height limit,
but then I saw this code in ulist():
```
	if(mode&WIN_FIXEDHEIGHT) {
		height=api->list_height;
	}
```

something Deuce added for SyncTERM and I don't think I've ever used before.
It works.

This also addresses the addresses with 65535 in them in the new debug-level
log messages "New packet (type x) created for linked-node" .

To complete the request from: Max (WESTLINE)

  Is it possible to do a new dateformat in scfg
  In sweden we using YYYY-MM-DD format as standard.

The default will be '/'.  Technically, any separator is possible by editing
the "date_sep" value in the global section of main.ini.  SCFG allows the
most popular separators: /.- and space.

... and YYYY/MM/DD for birthdate input/display.

Now set in SCFG->System (not toggle options) and stored in the "date_fmt" key
(new) in main.ini. The old sys_misc SM_EURODATE flag is deprecated (but used
to determine the default value of date_fmt when not present).

As requested from: Max (WESTLINE)

  Is it possible to do a new dateformat in scfg
  In sweden we using YYYY-MM-DD format as standard.

This completes the revert of commit c22063f9 from (Jun-2-2016). The Baja
part of that commit was reverted in commit 932fae30 (Nov-15-2016). This
behavior has proven to be surprising and annoying for JS mod developers
(e.g. the yesnobar.js and Nightfox's file searcher/scanner).

If we still need clearing of abort status after running JS "externals",
that should probably be done in exec_xtrn(), not here.

Should calm the clang warnings reported by Deuce:

e.g.
passing 'char *[18]' to parameter of type 'const char **' discards qualifiers in nested pointer types

CID 476253

The 4th enhancement request of issue #674

The other requests look a bit more involved than I'm willing to explore right
now. And Deuce reassigned this back to me. So that's probably all that's going
to be done.

Go ahead and fix false-positive CID 33482 by adding a NULL check to quotestr()

CID 462234

Even though smb_getmsghdr() just saves and restores the msg.idx_offset value
(not actually using it, but triggering this Coverity issue), this does seem
like better behavior and more consistent with the loadfiles() implementation.

The use from addfiles.js (the -readd option) implies this is what's expected.
And echicken was suprised the 'added' date/time-stamp wasn't udpated.

Nobody's really using this auxdata yet, besides echicken, so no impact for
others.