Use byte_estimate_to_str() to display upload/download byte totals (better
support for totals in gibibytes, tebibytes, etc.).

Ctrl-A - Select All
Ctrl-F - Filter IP address
DEL - Close Socket

Also, use Begin/EndUpdate() calls to batch updates to the ListView in Timer
tick (no visible difference, but it's the right thing to do).

I don't know why C++Builder increased the TextHeight value of this form from
13 to 15, but doesn't seem to really matter (or at least, I couldn't tell).

I don't know why this was set so wide (10 pixels), but that did help to easily
see that it was being placed in the wrong spot in the form (between the tool
button bar and the top panel). But we don't need it to be that thick. 1 pixel
is still enough to be able to grab it with the mouse and resize the top/bottom
panels.

For who knows how long now, the horizontal splitter that allows the sysop
to control the size of the top 2 panels (server forms), was displayed above
the top panel, not between the top and bottom panel, thus making the panel
heights not controllable. Weird. Change the order of making the controls
visible to insure that the splitter is displayed below the top panel and
on top of the bottom panel.

Also (non-functional changes):
Remove redunant mutex from client_on() - makes no difference.
Use try/catch in client_on() to try to catch VCL exceptions - doesn't catch
the "invalid index" error popups that we see on occasion. <shrug>

... so the [web] HttpLogFile setting in sbbs.ini couldn't be set using this
dialog. Been broken all this time.

Allow SFTP support to be enabled/configured in SCFG->Servers and
SBBSCTRL->Terminal->Configure.

SFTP session inactivity applies to 'H' exempt users too (intentionally).

Resolve build warning about unused var

... so no need to parse/strip them here.

This eliviates the issue of partial/corrupted UTF-8 sequences when spying on a
node serving a UTF-8 terminal.

Reads the new(ish) node*/terminal.ini file when it's changed to determine
the connected-client's terminal type/dimensions. Now reports the terminal
details in the spy form title/caption and if it's UTF-8, does a real-time
translation to CP437 (since F. Piette's terminal lib only supports CP437).
There is a bug here where if the data read from the RingBuffer is a
partial UTF-8 sequence, it isn't decoded correctly. Fix that later (?) if it
actually bugs anyone.

There's no PETSCII conversion/support added here. I expect to someday replace
this entirely (likely with something that uses cterm), so didn't want to
invest too much time into this.

But at least now spying on non-traditional ANSI-BBS clients isn't so terrible
to look at.

Still using BOOL where we need Win32 API compatibility.
Using JSBool instead of BOOL or bool where it matters.
Changed most relevant TRUE/FALSE to true/false too (though it's not as critical).

You shouldn't need to #include <stdbool.h> anywhere now - gen_defs.h should do that automatically/correctly based on the language/version/tool. In C23, stdbool.h isn't even needed for bool/true/false definitions (they're keywords), so we don't bother including stdbool.h in that case.
Microsoft didn't define __STDC_VERSION__ in their older tool chains (even though they were C99 compatible and had stdbool.h), so we use a _MSC_VER check to know that there's a stdbool.h we should use in that case.

For other/old compilers (e.g. Borland C) we #define bool/true/false following the pattern of stdbool.h (doesn't use a typedef).

I didn't convert UIFC yet.

This addresses issue #698

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.

... for server configuration dialogs

We need to get the NextItem *before* we delete the current one.

I'm not sure why this was in there, but removed it as appears to have
no effect:
	if(ListView->Selected == NULL)
		break;

Include the time-span of the login attempts in the reason string.

Ctrl-A in the Failed Logins dialog now selects-all rather than copy-all (just
use Ctrl-A, then Ctrl-C to copy all).

There's a hidden checkbox on the CodeInputForm now (explaining why the edit/
combo box is now moved up).

Renamed the "Perm Filter Threshold" to "Auto Filter Threshold".

Changed help text from "Permanent" to "Persistent"

The number of failed login attempts. It's something.

Now a sysop can "perm block" a client (IP address) for a limited amount of
time rather than always forever.

Add more displays of the ip.can details when actively blocking a client.

Moved twit/trash functions from userdat.c to trash.c

Running SBBSCTRL on Windows 11 with a 4K monitor looked horrible.
The default font sizes varied widely - I'm not sure why this wasn't
apparent before now. And the default font ("MS Sans Serif") is no longer
included in modern Windows versions, so when choosing a Log font, the
pre-selected font was just blank. So change use of "MS Sans Serif"
everywhere to "Microsoft Sans Serif" which appears to have been around since
Win95 and be the preferred alternative. I would consider Segoe, but that
wasn't introduced into Windows until Vista and I'm not sure (yet) what
troubles that might introduce. I'll experiment with a WinXP VM maybe
and find out.

Also:
For log message styles (e.g. colorization) based on log level, don't apply
a different font (Name) or size. This just looks terrible when this is done
and I don't think any sysops want that. Keep each log window using the same
font face (name) and size, just allow the color and style (e.g. bold, italics)
to change based on log severity.

This does increase the confusion with the Properties->Customize->Log Fonts
as the "Change Font" dialog still allows the sysop to select/change a font
face and size, they're just not saved/used. I coudln't find a way to remove
or disable these from the displayed TFontDialog form.

Removed backup_level option from save_cfg()

This seems kind of circular doesn't it? Anyway, add a new SCFG->System->
Advanced->Configuration Backup option to set the number of config (.ini)
file backups to keep (default is 5).

Eliminate the scfg -b option (used to manually over-ride the default
backup level of 5).

Fix for issue #542

Use the terminal server sem file check interval instead of node_sem_check
(it was only used in the event thread) and node_stat_check was only used in
the control panel, so just support a registry over-ride, but default to 5 sec.

These settings were artifacts from SBBS v2 (WFC mode), and not really relevant
or in the proper configuration place.

Each Synchronet server is now its own MQTT client. This means there's no
longer any MQTT logic in the Synchronet "hosts" (e.g. sbbscon.c, ctrl/*.cpp)
and none needed for SBBS NT services (they'll "just work" with MQTT).

This also means that just about everything (except for nodes, spam and hack)
is now published per-server (in the sbbs/BBS-ID/hostname/server/ topic branch)
and if you want aggregated totals or client lists, you'll have to do that in
your own MQTT client or dashboard.

I also removed the publishing of thread_count and socket_count topics as
they weren't universally supported across all servers and are of questionable
value. They can be added back later if determined to be useful.

Now support subscriptions (e.g. recycle topics, node input topics) in SBBSCTRL.
This required a lot of search/replace and fun with circular struct pointers.