hold the lock.  This should finally fix all the things I hope.

already held by the bitmap layer.

This fixes the Linux crash on exit in SDL when X11 mode is used (and possible
others).

a potential problem with grabbing vstatlock).  Call XCloseDisplay and terminate
the X11 event thread on exit().

This still does not prevent the crash on exit for Linux.  This appears to be
an issue with SDL.

setup_surfaces() was never called for overlay mode, resulting in the window
contents never changing size.

scaling but forces it to 2.  This is to allow two "pixels" for each "real pixel".

If we don't have two pixels, the chrominance values cannot be represented
correctly, only the luminance... resulting in a monochrome image.

JS model (bbs.scan_msgs() method).

was never used. This was intended to be a method for internationalization,
letting the sysop change which key is used as the uiniversal "quit" key.
This commit replaces most of the uses of the hard-coded 'Q' for quit wtih the
3rd charcter in the text.dat YNQP string. Some hard-coded menus still have the
'Q' key hard-coded and will need to be addressed later. The text.h YN index
macro was changed to YNQP and the JS text index variable name will change
as well.

draw the top line and first left vertical row in a file list box.  The rest
of the box was drawn in whatever attribute text.dat left it in.

Valgrind report).

Optionally, external modules may be executed in place of "built-in" operations
for:
- reading mail (email or netmail)
- scanning posts (searching/scanning/reading a single sub-board)
- scanning sub-boards (all, one, or a group)

Each of these may be configured (in SCFG->System->Loadable Modules)
with command-line options for a total length of up to 63 characters.

Note to module programmers: each module here will be passed additional
command-line arguments to indicate how or why the user operation was invoked.

For the Reading Mail module, the 'which' value (in decimal) and the user-number
is passed (in decimal). Usually the user-number will be the current user logged
in, but not always (e.g. if the user is a sysop and reading other user's mail).
The 'which' values (defined in load/sbbsdefs.js) of MAIL_YOUR, MAIL_SENT,
and MAIL_ALL must be handled (MAIL_ANY won't be used).

For the Scan Posts module, the sub-board number and scan mode (both in decimal)
and the 'find' string (text being searched for) are passed as arguments
(in that order). The scan mode values (defined in sbbsdefs.js) are the same as
those supported by bbs.scan_posts(). All of the values should be supported
and they can be combined (e.g. SCAN_CONST|SCAN_NEW
and SCAN_NEW|SCAN_TOYOU). The 'find' string is only used if the SCAN_FIND mode
bit is set. It is the responsibilty of the module (if configured) to enforce
sub-board read access restrictions.

For the Scan Subs module, the first argument is 1 if "all subs" are being
scanned, 0 otherwise (normally the user is prompted for the breadth of the
scan in this case, but that's up to the module author), and the scan 'mode' is
passed in decimal, in that order. If the SCAN_FIND mode flag is passed in, this
module should prompt the user for the text string to search for. If this module
is not configured, the Scan Posts module will be executed for each sub-board
scanned.

Recursion protection was added, so it is actually possible for the Read Mail
module, for example, to call bbs.read_mail() and it'll work, but why would you?

If any of these user operations are initiated during logon, at the request of
Baja or JavaScript module, or whatever, and if the module is actually
configured (and not already executing to handle the operation), the module
will be executed in-place-of the built-in functionality. Feedback welcome,

for the four current fonts... -99 (uninitialized), and -1 (loaded font).

-99 was supposed to be automagically converted to CP437, but a bug in
revision 1.40 (Feb 27, 2015) made this not happen.  As a result, the font
was copied from an index of -99 in the font data array.  This was garbage
on some platforms and appears to have caused crashes in others.

by access_d.  Broken since v1.18 on Feb. 10th,  2015.

ID is a pointer on at least FreeBSD, cast to uintmax_t instead of DWORD.

scripts global scope (as opposed to js.global which is the instance global
scope), and having exit() define exit_code in js.scope instead of js.global.

This also sets exit_code in js.scope to null when preparing to execute a new
script.  If a new script starts in the same scope as an old one, the old
exit_code value will be destroyed.

This should only impact scripts where js.global != js.scope (bbs.exec()ed,
and mailsrvr)

(or by adding NOCIRCULARFWD to your sbbsecho.cfg):
When "Circular Path Detection" is enabled (the default), the old behavior was
to still forward the message to any links (if there are any), but not import
the circular/looped message (likely a dupe). Now, if you set this new option
to no (or add "NOCIRCULARFWD" to your sbbsecho.cfg), the message will be
completely ignored and not fowarded to any links (if there are any).
If you have no downlinks or you have circular path detection disabled, this
new option does nothing. The default is the old behavior (forward circular
messages).
Also updated the Toggle Options help text in echocfg (many options weren't
documented.

really may to what is listed.

follow the special boolean keywords "True", "Yes", or "On", treat the value as
a logical true (1). Previously, if the boolean keyword was followed by a
semicolon (no whitespace separation) or any text with whitespace separation,
the value would be treated as a logical false (0). The  example sexpots.ini at
wiki.synchro.net has comments following some "true" values which caused them
to be interpretted as "false". Bug reported via reddit by FozzTexx.

This will also enable SVID stuff, but that appears to be unavoidable.

See the following URIs:
https://lwn.net/Articles/590381/
https://sourceware.org/glibc/wiki/Release/2.20#Deprecation_of__BSD_SOURCE_and__SVID_SOURCE_feature_macros
http://www.gnu.org/software/libc/manual/html_node/Feature-Test-Macros.html#index-_005fDEFAULT_005fSOURCE

be set and read using the POSIX macros and related (currently Linux-only).

this read() call will block indefinitely. Fall-through to pseudo-random seeding
if read() fails. Fix for FozzTexx-reported problem on reddit.

video stats.  This makes the C64 80 column mode look less stupid.

This matches the overlay mode selection.

new_scaling and old_scaling to prevent setup_surfaces() from being called
again while the window is initially being set up in a mode other than the
default 80x25.

Fixes a Windows crash when starting in other modes.

hash entries will then have incorrect or invalid message numbers.

download path via SHGetKnownFolderPath(), don't append "/SyncTERM", since for
Vista and higher, FOLDERID_Downloads is used as the "Default location to save
all downloaded content"

single argument.  Imapged Global War continent maps at least.

Thanks for the bug report Digital Man!

couple global pointers (win and new_rect), and move upd_rect, rectspace, and
rectsused into automatic variables in the event thread function.