warning: result of comparison of constant 100000 with expression of type 'uint16_t'
(aka 'unsigned short') is always true

./scfg.h:80:9: warning: 'SUB_HDRMOD' macro redefined [-Wmacro-redefined]

This is always going to call the terminal server's lprintf function (when used
with libsbbs.so/sbbs.dll) which is probably not what was intended.

Resolve reported clang warning:

inkey.cpp:592:20: warning: implicit conversion from 'long' to 'int' changes value from 2147483648 to -2147483648 [-Wconstant-conversion]
         if(!term_supports(MOUSE))
             ~~~~~~~~~~~~~ ^~~~~
 ./sbbsdefs.h:574:19: note: expanded from macro 'MOUSE'
 #define MOUSE           (1L<<31)                /* Mouse supported terminal                             */

This is hacky cruft here. We shouldn't have the declaration in multiple
places. It probably shouldn't be in sbbs.h.

load_cfg() calls free_cfg() before do_cryptInit() is called, so the ssl_rwlock
was uninitialized here.

Holding the lock around session establishment should not be needed,
but we need to protect tls_certificate read and usage.  Since we
don't have rwlocks in xpdev (yet?), hack together a crappy rwlock
that does what we need.

Also, remove "CONSECUTIVE", which doesn't really make sense when the number
of login attempts in 1.

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

Use lower case y/w/d/h/m suffix.

If a duration is an exact multiple, don't display ".0" fraction. This is not
consistent with byte_estimate_to_str() string generation, but I think it's
more in line with human expectations.

Don't display "90d" as "12.9w" (unless the requested unit is one-week).

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

Changed help text from "Permanent" to "Persistent"

More readable/friendly log messages and ip.can reason strings

Sometimes you want to see "1.5 minutes" (or "1.5M") intead of "90 seconds"
(or "90S")

I noticed some left over questionable use of ulong here in byte_count related
functions, so fixed that.

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

Update wording and add more help text.

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

For symmetry

I wanted a couple of features for filters (e.g. blocked IP addreses):
- expiration date, optionally (only block for a limited time)
- display details of reason for filter in log messages (at time of block)

I've been thinking for some time that these files should be converted to .ini,
but then it occurred to me that I could do a sort of hybrid where the metadata
was key/value pairs tab-delimited from the search-pattern (first text on the
line). This is backward comaptible, relatively easy to view/edit by hand, and
extensible (easy to add/remove metadata fields in the future). So they'll
remain as text/*.can files.

The maximum line length for findstr/trashcan parsed files extended from 255 to
1000 characters.

Moved all trashcan-related functions from scfglib1.c to (new file) trash.c.

For the first time, I actually tested a build on WSL *before* committing to
Git. So, this *should* pass CI the first time. :-O

The output of this function was not ISO-8601 complaint (blush) and was not
parsable by isoDateTimeStr_parse() (returned -1).

e.g. "20231217T011437-480" rather than "20231217T135222-0800" (in PST)

Positive UTC offset (eastern) zones would be even worse (the + separator
would be missing).

SlyEdit: Now using msg_area.sub[code].settings to check for posting with real...

See merge request !377

So move to nopen.h