We've never really cared how many times the ring buffer has become
empty, how many times data was added to it, or how many times we've
been over the highwater mark.  These have effectively always been
event signalling, with extra hackiness to clear "extra" semaphore
posts.

This commit removes RINGBUF_SEM entirely, and uses events for
everything.  There's an empty event (set when the ring buffer is empty),
a data event (set when the ring buffer is not empty), and a highwater
event (set when the ring buffer has at least highwater mark bytes).

A RingBufWrite() will set data and highwater events if applicable,
and clear the empty event.

A RingBufRead() will set empty event and clear data and highwater
events if applicable.

RingBufReInit() will now set the empty event, and clear the data
and highwater events.

These are the only actions the RingBuf API will perform on the
events, it does *not* clear the highwater event on a RingBufWrite()
if the buffer does not have enough bytes in it for example, this
will *only* be done by RingBufRead() or RingBufReInit().  This
allows consumers to force specific behaviours (such as forcing
the highwater event on shutdown to prevent waiting for it).  Since
the current code was able to deal with the semaphores having
arbitrarily high counts, the existing code shouldn't have any
issue with this.

For things that want to shut something down, we're now setting both
the data and highwater events to ensure it doesn't wait for a
timeout (even for things that don't use highwater like the inbuf).
The RingBuffer API should grow a thing to do this (RingBufferFlush
perhaps?) rather than the consumers poking into the innards
arbitrarily.

Tested on the webserver and RLogin server and seems to be working
great.  sexyz builds.  It seems there's some Windows thing that
uses the ringbuffer sem for something, but I couldn't figure out
what... updated the build file, but no clue if that's broken or not
now... I'm sure DigitalMan will be happy to fix it if CI doesn't
catch it. ;)

This should allow the console object to grow a "flush" method that
will set the highwater and data events.

Currently, sbbs.exe only
Includes non-Unix build fix in sbbscon.c for issue introduced in previous commit

I just wanted to reuse findstr() in vdmodem.c and I fell down this hole :-)

findstr.* is new (findstr() related functions moved from str_util)
getctrl.* is now finally the real home of get_ctrl_dir(), moved from str_util
trashcan* functions moved from str_util to scfglib
other scfg_t dependent functions moved from str_util to scfglib

net_addr() appears to be a function that was never created/used (?)

This will definitely break the *nix build, for now.

So it can be reused for other projects more easily

Inspired by Blocktronics (and other ANSI art group) packs' FILE_ID.DIZ/ANS files:
* Support (and prioritize) FILE_ID.ANS
* Convert ANSI color/attribute sequences in DIZ files to Ctrl-A equivalent (uses SAUCE width and ICE color, if specified)
* Don't treat DIZ as a series of lines, they're not always nowadays.
* New putmsg() mode: P_INDENT to print files indented by current column
* Display full (up to 64-char) filenames in lists when using 132+ column terminal.
* Use the Author, Group, and Title fields from the SAUCE if present/non-blank
* 2 new text.dat strings: 301 (FiAuthor) and 302 (FiGroup)
* Also fix bug with repeated Cost header field on bulk-uploaded files.

I know this'll break the *nix build (sauce.c dependency), but I'll fix that next.

This won't impact Synchronet as it has a separate signal handling
thread, but we still need to behave properly for processes that
don't.  I'm also saying that ENOMEM does not indicate a disconnection,
though it may be better to pretend it was disconnected...

This fixes the stat() issue on Windows XP/2K3 by allowing sbbs to benefit
from the run-time library updates that Microsoft releases periodically
(like https://www.microsoft.com/en-us/download/details.aspx?id=53840).

For more info on the stat() issue which caused all kinds of sbbs errors
(e.g. creating directories initially, but a lot more):
https://stackoverflow.com/questions/32452777/visual-c-2015-express-stat-not-working-on-windows-xp

Since we are using cryptlib which requires the MSVC runtime DLL anyway
(it is the default build behavior of MSVC), we weren't really gaining
anything from statically linking the CRTL (LIBCMT.LIB). And for some reason,
an up-to-date MSVC2019 still has (links-in) a LIBCMT.LIB file that includes
this stat bug. All the online help resources I found just to seem to suggest
updating the CRTL DLLs (on the target system), with no mention of any fixes
available for the static CRTLs on the build system. But with the no gain
from ...

js_socket.obj : error LNK2001: unresolved external symbol _in6addr_any

Visual Studio 2017 - Windows XP (v141_xp) toolset

New function (derived from sbbs_t::utf8_to_cp437()): unicode_to_cp437()
New utf8 functions: utf8_replace_chars(), utf8_str_is_valid().
utf8_getc() enhancement: val arg may be NULL (for length/validation uses).

Convert quoted UTF-8 message text to CP437 when terminal is not UTF8.

Set Fido CHRS: UTF-8 header field when posted message is UTF-8.

Removed v4upgrade from sbbs project.

You'll need to perform a clean build.

translation.

You get a warning if a minimum version is specified and SubSystem is not.
WINDOWS is for "applications that don't require a console" (like the DLLs)
and apparently the only difference is in standard (main/WinMain/etc) entry
point handling... which shouldn't be an issue in the DLLs.

If DigitalMan uses the Edit and Continue feature, he can fix it.  :-)

defines XPDEV_THREAD_SAFE (not currently used in Windows builds) and
LINK_LIST_THREADSAFE (notice the inconsistent use of underscore :-)
Use of this property sheet fixes the problem with the terminal server global
variable 'uptime' getting corrupted when jsrt_GetNew() called listInit() from
js_rtpool.c which didn't #include sbbs.h and therefore had a different idea
about the size of link_list_t and thus corrupted the global data region
(zeroing out the 'uptime' variable, probably amonst other important things).

application" error message (when run on XP) and reportedly will allow target
executables to run on non-SEE (pre-Pentium III) CPUs. Seriously, anyone really
running Windows XP on a Pentium II today? I guess it's possible <shrug> and we
really get little benefit from SSE in Synchronet.

I couldn't get Windows 2000 running in Hyper-V, so I guess Windows 2000 is
now officially unsupported by Synchronet (and long unsupported by Microsoft).

Thanks to Android8675 for the bug report and Rushfan for the solution tip.

of these files for now (if you don't want to upgrade just yet).

(e.g. src/js/win32.release/*).

JavaScript-C (SpiderMonkey).