strrchr() here to find terminating chars (quotes, parens, brackets).
e.g. '"Joe Shmoe" <joe@shmoe.com>, "Fred Smith" <fred@smith.org>'
would be parsed as 'Joe Shmoe" <joe@shmoe.com>, "Fred Smith'.

'data_length', but not always (e.g. may include text from some header
fields, excludes any non-text data fields).
Mark 'data_length' msg header property as read-only.

back in 1993, but were never needed/used.

sendfile() no longer logs "attachment" when a file description is provided.

download_file_attachments() and expose via new JS "bbs" method. Currently
this only reall works for the mail base.

since the smb_t already contains a subnum and we were passing a pointer to the
sbbs_t::smb to lower-level called-functions anyway.
Let's not mix-up class-scope with function arguments.

Fix the missing carriage-returns in the shell (bash) prompts by always building with the stderr logging
support (in *nix builds) - but run-time disable as desired via EX_NOLOG option. I've been wanting to get
rid of that "XTERN_*" macro for a long time anyway (it's "XTRN" damn-it!). :-)

intercepted output to stderr won't be logged.

Since QUOTEWRAP *is* used, just define that bit flag specifically.

list (smb_list) for thread-safe SMB stack storage.

of the message header so that functions that need it (e.g. bbs.show_msg_header)
don't use/show stale data. This change requires the updated smb_copymsgmem()
which clear/sets message convenience pointers upon copying hfields from one
message header to another.

(objects, in the same format as returned by the get_mgs_index() method)
much faster than iterating through a loop, calling the get_msg_index() method
for each message. If you want to load messages (e.g. headers, text), filtering
by criteria found in the message index (attributes, to/from user, subject CRC)
loading a list of indexes and filtering before calling get_msg_header() for the
selected messages is much faster than previously available MsgBase object
methods (e.g. get_all_msg_headers()). If you don't need to filter the loaded
messages (you really want *all* message headers), then get_index() is of no
benefit to you, the script-writer. This is most useful for the "mail" msgbase
where selective loading of messages is more common.

Ctrl-A (ASCII 1) char. This is wrong. A literal Ctrl-A sequence is ^AA.
I'm only addressing one of those instances in this commit since it *also*
appears to be an off-by-one bug where it's treating *all* Ctrl-A sequences as
though they were ^AA - so just #ifdef'ing out until Deuce takes a look at this.

(use the sysop 'D'elete command to quickly delete a range of messages).

js_put_msg_header (MsgBase.put_msg_header) - we can't free the memory
associated with 'gotten' msg header. Just use the header offset from the
header retrieved via MsgBase.get_msg_header() - for fast lookup.
Also fixed an innocuous extra increment of 'n' in argv/argc loop.

Updated help text and option name, a bit.

Linux system limitations and user/port configurations of sbbs.
Add some parens around bit-wise "and" (&) checks too.

Nobody checks the netmail() return value apparently, but this has been a bug
since ... forever.

- bbs.show_msg()
- bbs.show_msg_header()
Re-worked the JS bbs.netmail() implementation
sbbs::show_msg(), show_msghdr(), msgtotxt() now take an smb_t* argument
(don't use the pseudo-global 'smb' in these functions any longer)
sbbs_t::putmsg() and JS console.putmsg() now accept an optional orig_columns
argument to specify the original column width of a text for intelligent
re-word-wrapping (e.g. as taken from a message header field). Previously, the
original-column value was hard-coded to 80 columns (technically, 79).
sbbs_t::show_msghdr() no longer sends a CRLF if the cursor is already at the
top-of-screen (TOS).
sbbs_t::show_msg() now uses the stored "columns" msg header fields to pass to
putmsg() to intelligently re-word-wrap message bodies for display.
sbbs_t::show_msg() and msgtotxt() return bool now instead of void.
JS MsgBase.get_all_msg_headers() now supports an optional "expand_fields"
argument (defaults to true). I contemplated just getting rid of the (few)
expanding header fields (more like default-value-header fields, like 'id'), but
decided against it, at least for now.
JS MsgBase.put_msg_header(), the "number_or_offset" argument is optional and
not needed if a header object argument is provided. Make this clear in this JS
docs for this method

Note:
I sat on this commit for a while because I noticed occasional errors like this:
    Node 1 <Digital Man> !ERROR 2 (No such file or directory) (WinError 0) in
    readmsgs.cpp line 217 (sbbs_t::loadposts) locking
    "path/to/sub" access=-100 info=smb_locksmbhdr msgbase not open
started cropping up after introducing these changes and which I never
root-caused. But after a clean-build and waiting a week, I haven't seen it
again, so hopefully it was just a incomplete rebuild issue and not a new bug.

character limit imposed by FidoNet message "to" fields, in sbbs_t::netmail().
Use the regarding-message from_net field when a 'to' field is not passed to
sbbs_t::netmail()

IPv6 commit of 2015:
"OutgoingV4" is now "OutboundInterface" and
"OutgoingV6" is now "OutboundV6Interface" (which is not yet used)

Fix age-old bug with Borland/C++Builder built executables (Windows):
to achieve compatibility with  the default __cdecl symbol naming rules of
Visual C++, we were using __stdcall convention for DLL functions when
building code with Borland/C++Builder tools and using the default (__cdecl)
convention when building with Microsoft (Visual C++) tools. Although this
allowed symbols to be located when linking, the calling convention mismatch
caused a stack cleanup issue that very rarely manifested itself in a bug
(e.g. exception of some kind in sbbsctrl.exe, usually). Mismatching
the calling conventions was unintentional (I thought the default for MSVC
DLL functions was __stdcall) - but since the calls to MSVC-Built DLL functions
worked 99% of the time, I didn't realize there was an underlying issue. So I
now work-around the DLL symbol naming mismatch using a command-line option (-a)
passed to implib in src/sbbs3/ctrl/makelibs.bat

I had previously worked-around exceptions when calling MSVC DLL functions in
sbbsctrl.exe by calling the problematic DLL functions from a timer tick handler
rather than a user control (e.g. button) event handler. Those work-arounds can
now be removed.

The erroneous "DLLCALL" definition design pattern was replicated (copy/pasted)
to many other projects' header files in cvs.synchro.net. In the future, we may
want to just remove all instances of *CALL since they now serve no purpose and
appear as useless "Kruft" (but do allow us to more-easily globally change DLL
function calling conventions if/when necessary in the future).

Don't store a columns value of 0 (the default).
Use SAFEPRINTF in place of sprintf() in parse_control_line().

FidoNet "Kludge line" (control line): "\1COLS: <columns>\r" where <columns>
is a value between 0 and 255 and a value of 0 is special, meaning "unknown"
and not normally specified (this is the default assumption when there is no
"columns"/COLS header field). When a message editor column width is unknown,
is is normally assumed to have been 80 columns for word-wrapping/re-wrapping
purposes when displaying the message text.

This feature has worked well for Synchronet's QWK networking (i.e. there are
far fewer instances of word-wrapping/re-wrapping issues when viewing messages
on DOVE-Net), so I decided to support this message header field over FTN
(SBBSecho) as well. Hopefully other FidoNet software authors will notice and
support this header field in the future as there are still numerous examples
of word-wrap issues when viewing FidoNet messages. At least Synchronet <->
Synchronet systems over FidoNet should be able to re-wrap and display all
message text nicely when both ends support this kludge line.

Incremented SBBSecho version number to 3.07.

- filenames must begin with an alpha-numeric char. Might want to relax this in
  the future if it's a problem, but generally filenames on BBSes do begin with
  alpha-numeric characters and this will help us to identify an ignore
  "garbage" filenames in listfiles.
- always check if the file actually exists, even when parsing the length of
  the file from the listfile. This will also help us to ignore garbage
  filenames.
- also removed an inexplicable unpadfname() call. Filenames in file lists
  should *not* normally be padded (like "this    .txt") - so I'm not sure why
  this was in there. Perhaps for lists generated from filelist.exe (?). Anyway,
  out of an abundance of caution, removed it. Padded filenames are going away.