- Support LCF (Last Column Flag) mode per DEC STD-070
  (Despite years of protest that it's stupid)
- "Properly" support CSI 7 m and CSI 27 m
  Now, when in "Negative Image" mode, changes to the foreground
  change how the background is drawn and vice-versa.  Perviously
  this command just swapped the two values and called it good.

Fix bad and poor unicode mappings, add support for sending Insert
and Pipe.

Toggled using backtick.
Current state is shown in the status bar.

Since we previously couldn't actually *show* the status bar in
ATASCII (or C64) mode, enable that as well.  This means supporting
40-column status bars too.

We still default status bar to off for those modes, because that's
likely what people actually want.

Also, it seems ENTER was broken in ATASCII mode, so fix that as well.
Implements SF feature 61

warning: ‘maxval’ may be used uninitialized
warning: ‘inch’ may be used uninitialized

At the same time, add BD, BE, PE, and PS to the terminfo entry.

Note that it seems this is "normally" detected by seeing if $TERM
contains "xterm" which shouldn't work with SyncTERM (which is wildly
incompatible), but the terminfo source file here:
https://invisible-island.net/ncurses/terminfo.ti.html
Gives us hope in the form of this comment:

https://invisible-island.net/xterm/xterm-paste64.html

Bracketed paste was introduced by xterm patch #203 in May 2005, as part of a
larger feature for manipulating the clipboard selection.  Few terminals aside
from xterm fully implement the clipboard feature, but several copy this
detail.  The names for the extended capabilities here were introduced by vim
in January 2017, but used internally.  In 2023, vim patch 9.0.1117 is needed
to work with this change.

That is to say that it likely won't work on anyone's system today
(except maybe Cyan's), but it may magically start working in the
future... assuming tic supports these capnames.  No real clue there
since there's absolutely no termcap support, and I use FreeBSD.

Some Linux systems ship with a reentrant ncurses library that does
not have an ESCDELAY variable.  For now, simply don't allow control
over ESCDELAY on the systems since we also currently have a global,
and so can't use set_escdelay() as intended.

Also, in ripper, stub out all the stuff that's used when HAS_VSTAT
is not defined.  This makes most of the code not compiled when it's
useless anyway.

Fix a couple warnings while we're here.

warning: format ‘%s’ expects argument of type ‘char *’, but argument 4 has type ‘void *’
warning: ‘sprintf’ writing a terminating nul past the end of the destination

not scale it in one colour space before translating it to a different
one.

Also, since almost all PPMs will use a maxval of 255, compile that
in as the default so we don't need to generate it.

You can copy whole, or portions of a PPM file from the cache directory
to the screen, optionally applying a mask.  The mask can be specified
as a base64-encoded bitmap or as a PBM file in the cache directory.

You can also copy portions of the screen into an internal buffer, and
draw from that internal buffer.  There's plans to support loading an
image file from the cache directory into the buffer as well.

Portions of the buffer can be copied to the screen, optionally
applying a mask as with drawing PPMs.

There's also plans to support copying a PBM file into a mask buffer.

I've added the syncterm-bounce.js script which simply bounces the
SyncTERM icon around the screen like the classic screensaver we all
hate.  I initially wanted to replace the spinning cursor with it,
but there doesn't seem to be a way to replace that with a script. :(

To use the script, just add the text:
@EXEC:syncterm-bounce.js@ to the end of your logon.js script.

Log in to nix.synchro.net with the latest nightly build or build from
git to see the script in action.

the start of wrapped function call continuation lines, but at the
end of struct initializers/enums/etc lines.  I think the least bad
is commas at the end, especially now that it's got the happy
four-space indent for continuations.

I may play with this more later, but this seems to be good for now,
we'll see how it works out in actual use.

I tried a space after too, but that's weird as well and easily
confused with multiplication at first look.

Run uncrustify on this mess.
There's a few small oddities (especially in enums), but this is
much better.

There's no reason to be aggressively ancient.

Previously, b64_decode was being asked to decode past the end of
the application string.

Fix off-by-one error with b64 cache store buffer size.

already in binary mode.

Should fix Sourceforge issue 91

This is for weird embedded systems where RTS is not supported by
the communications channel, but is actually controlling something
else (TX, Bootloader update mode, etc).

New Medium impact and a low impact issue still needs to be triaged.

While we're doing that, actually use it in SyncTERM so the offline
scrollback retains fonts.

Also, fix an issue where the current mode would be updated with
the custom parameters when you changed them.

Finally, remove some unused variables.

Now that ALT-Up/Down no longer have an effect on window size, they
can go back to their previous bindings of changing the emulated
output speed.

At the same time, remove AltGr support from keysym parsing since it
should be properly handled by the text input stuff now.

Use remaining bytes divided by CPS rather than total estimated time
minus elapsed time.

We squirrley on resumed ZModem downloads.

The option basically controls forced EGA mode and reported terminal.

There's a comment saying we set key=0 when we consume it... do so
in a couple cases where it wasn't done.

Range check the key before sending to the remote.

This should not actually do anything different, but in the future
if things are changed at least the comments won't be misleading.

This is used by some BBSs to enable encryption without needing to
integrate the BBS user base into their SSH server (and presumably
so they don't need to run multiple SSH servers).  All users log in
with the same username (ie: "bbs") and no password is requested or
required.

Once the BBS starts, it prompts for the BBS user name and password
as normal.

In SyncTERM, the user/password/syspass fields are redefined as
SSHuser/BBSuser/BBSpassword and they are moved around when you
change the connection type.  This means that if you change a listing
that has a syspass to SSH (no auth) and back, the syspass is lost.

I'm not sure if I plan to fix this or not.

Some broken protocol drivers (like sz) don't send a YModem terminate
at the end of a batch (or maybe just after a single file?) so SyncTERM
ends up trying to fall back from G to CRC-16 to 8-bit before ending.

This detects when the last known file was received, and if the YModem
header that follows is not correct, aborts the transfer.