Moved crc* and md5.* to src/hash

Removed v4upgrade from sbbs project.

crc* and md5.* was moved to src/hash
base64.* was moved to src/encode

You'll need to perform a clean rebuild.

You will need to perform a clean rebuild.

You will need to perform a clean rebuild.

You'll need to perform a clean build.

You'll need to perform a clean build.

translation.

MIME-encoded headers.

translation from CP437 -> UTF-8 and only when using high-level text output
functions - so the output from native/DOS doors and scripts that use low-level
output methods won't be translated.
UTF-8 is auto-detected (only) at this time during answer (before login) by
sending a ZWNBSP and checking (via ANSI) if the cursor position moved - an
idea "borrowed" from Ozz Nixon (aka SqZ).

This commit requires the new "encode" library (src/encode), so you may need
to perform a cvs checkout to get that module!

Prepare for upcoming "hash" library.

this insures:
1. the timestamp always includes the seconds
2. the tiemstamp is always in 24-hour format (no am/pm indication)

For systems that are configured (in SCFG) for "Military" (24 hour) time format,
the error.log timestamps should appear the same as before.

Use "save/restore" uifc.list() mode for "Save Changes" prompt - no need to
leave the prompt visible while saving changes.
Display pop status while saving changes to config file.

Copy/paste errors from 2002 (changes -> uifc.changes in the help text).
Use "save/restore" uifc.list() mode, rather than "remain active" for
"Save Changes" prompt - no need to leave the prompt visible while saving
changes.

When processing area manager netmail messages, SBBSecho can modify
(add/change) keys in the [node:*] section of the sbbsecho.ini file. Although
SBBSecho would read node sections that had a domain (e.g. 5D address) just fine
when processing area manager changes and writing those changes back to the
sbbsecho.ini, only 4D addresses (no "@domain") were used in the section naming.
This could result in duplicate node sections being created in the sbbsecho.ini
file (one with a "@domain", one without) and then "bad things" could happen
(e.g. BinkP authentication failures, packet authentication failures, etc.).

Now, when SBBSecho writes linked-node setting to the sbbsecho.ini, it first
checks for the full 5D address of the node and if that section exists, modify
it, otherwise fall-through to the 3D/4D address of the node for the sectoin
naming.

getting kind of crazy common now and being employed even when totally
unnecessary (e.g. encoding strings that contain just plain ASCII):
- normalize message header fields, when possible
- normalize UTF-8 encoded characters, when possible (e.g. special punctuation
  chars)

This allows text filters (e.g. subject.can, name.can) to work on MIME-encoded
header fields and notifications about received e-mails are legible to humans.

Encoded-words that contain actual non-ASCII/CP437 chars (e.g. foreign symbols,
emojis) are left as encoded-words to be dealt with by whatever displays the
message header.

Special handling of folded normalized field values was necessary because
"White space between adjacent 'encoded-word's is not displayed." (per RFC 2047)

line 34: Error: can't open \sbbs\exec\undefined.js: No such file or directory

This introduces a new request field send_content which indicates if the
content should be sent.  This covers various cases like HEAD responses
where there's an entity, but no content is sent as well as 204, 304, and 1xx
responses where there is not even an entity.

writebuf() will now enforce this, so there's no need for various checks
throughout the code to see if data should be sent or not.

Also, we now only set sent_headers after the headers are sent.

1) Send Content-Length even if we will be closing the connection.
2) Send the highest HTTP version in the status line that has the same major version.

2a98aeb09190301ba782ba2f79837332ae277ac93851d3066e63fecf6abe6f2a) as patched
by build/cl-*.patch and built with MSVC2015 for Win32-release.

I had to remove eap*.c from cryptlib32.vcxproj file to get it to build, but no
other changes.

resolved host-name on "Hostname:" log lines.