Double-check that the user has access to both the directory and the containing
library before allowing a download a file.

directory or library does not exist. (Thx DM)

Fixes error: ReferenceError: MGS_HFIELDS_UTF8 is not defined
when attempting to post a poll.

Merge branch 'master' of github.com:echicken/synchronet-web-v4

(Jump back to #fTelnet anchor when doing the click thing on
a clickable click thing to do the thing.)
Complaint courtesy of Android8675309

Don't display the name of messages posted with the anonymous attribute
and force messages posted to anonymous-only subs as anonymous.

total credits.
Set an 'error' property on reply if file not found or not
enough credits.

The User.downloaded_file() method has been enhanced to accept a directory
code and a filename to do "all the things" expected after a file has been
successfully downloaded. Use the method.

begin spanish translation

in the mail and forum pages.

If modopts -> [web] -> forum_no_spam, then filter spam messages
in the forum.  (Maybe make this more advanced in the future so
users can see these messages if they want to.)

When posting a reply-message, if the original "from" field is the
current user's alias, then reply to the original message's "to"
value instead of the "from" value. This is also how sbbs handles
reply 'to' fields.

Using Linux top, long-running (hundreds of hours) httpSess threads were seen
consuming ~15% of a CPU core. This loop calls time() and yield() in a tight
loop, so instead mswait(50) (milliseconds), which reduces the CPU utilization
considerable (down to < 1%), but will slightly impact the frequency with
which the events callbacks are invoked. A better scheme would be to block
while waiting for an event or a timeout (e.g. 1 second), so this is not a
great solution. More of a work-around.

Some messages come from non-English locales with non-UTF-8 charsets
(e.g. CP437), so their to/from fields may contain non-ASCII/non-UTF-8
characters (e.g. "Björn Felte") - so convert these fields (to/from)
to UTF-8, as needed. Uses the new(ish) utf8_encode() function, so you
must have a recent v3.17c build.
I did not transcode message subjects as I'm not clear how they are stored
and copied here. That's probably something better handled by echicken.

We don't (yet) support UTF-8 sequences in telegrams (short messages to users).

Respect the local "allow dupe realnames" setting.
Slightly more careful checking of some things.
More to come.

If temp/webv4.zip exists, prompt to overwrite it (default: Yes).
If No is selected, download will be bypassed and the existing
archive will be extracted.
Workaround for those times when downloads from GitHub fail.

newuser_level
newuser_flags1
newuser_flags2
newuser_flags3
newuser_flags4
newuser_exemptions
newuser_restrictions

When message header.is_utf8 is true, don't do the CP437->HTML entity
encoding dance.

There's a setting in SCFG->System->Toggle Options:
"Include Sysop Activity in System Statistics"

This option prevents sysop logons from being "counted" for stats
purposes as well as from being added to the logon list. Make this
so for web logons too.

When run with a build that includes utf8_encode() (new global JS
function), use it to convert the user's .sig file from CP437 to UTF-8.

When creating a new message (post or email), set the auxattr flag
MSG_HFIELDS_UTF8 since we support UTF-8 chars (not CP437) in message
header fields (e.g. to/from/subject). Requires updated load/smbdefs.js

using the FTN charset method (since we're not creating MIME-encoded messages
here).
Convert .sig files to straight-ASCII, for now. We really need a CP437->UTF-8
conversion routine, don't have one yet (in JS).
Also check the MsgBase.open() return value.

validation.

instead of any other monkey business (this is simpler and safer).
We'll also increment the user's login counter on success, for now.