Back out echocfg.c changes.

With this option enabled, zone/domain mappings from ctrl/ftn_domains.ini are
used to get the outbound directory name, and the orig/dest domains for type
2.2 packets.

This allows supporting 5D addressing in sbbsecho when zones do no overlap
between domains (the normal case).

toggle "EchomailNotify" setting in sbbsecho.ini.
Also changed "NetMail Options" menu to "NetMail Settings" and "EchoMail
Options" to "EchoMail Settings".

- If you are upgrading from SBBSecho v2.x, run "jsexec sbbsecho_upgrade.js"
  to convert your ctrl/sbbsecho.cfg to the new ctrl/sbbsecho.ini.
- Major code overhaul/re-write/modernization
- ArcMail/Attach/FD mode NOT TESTED: beware if you're using this style mailer!
- New features:
+ Easier to manage configuration file (sbbsecho.ini)
+ Multiple sysop aliases supported (for receiving netmail)
+ Mutual-exclusion-lock file (ctrl/sbbsecho.bsy) to prevent accidental
   concurrent invocations of SBBSecho
+ FileBoxes (optional inbox and outbox per node, only in BSO mode)
+ EchoList 4-char "flags" are now 25-char "keys" and much easier to deal with
+ Maximum msg age configurable for NetMail and EchoMail (separately)
+ Configurable "Area Manager" user name (default: SYSOP)
+ Configurable "Default Recipient" for netmail (default: SYSOP)
+ Far fewer command-line options, more settings in EchoCfg
+ Old command-lines will still work, but most of the legacy options are just
   ignored now. Run "sbbsecho -?" for command-line syntax and options.
Other improvements:
+ All Fido kludes, including PATH and SEEN-BY lines are stored in the
   Synchronet Message Base, always (can't be disabled)
+ Better security for inbound EchoMail (passwords are always enforced)
+ More comprehensive log output (the log output is more of a priority than the
  console output now)
+ Increased accuracy for recipient user name/alias matching
+ Higher-level of uniqueness to generated packet filenames
+ All temporary files (e.g. packets in process) are created in an
   SBBSecho-specific temporary file directory
+ No longer auto-terminates when any local key is pressed: use Ctrl-C/Break
   instead to initiate a graceful premature termination
+ Much more help text in echocfg
+ Better organization of settings in echocfg
+ Optional per-node "comments" for use in echocfg->Linked Nodes

signedness

(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.

file. Previously, any threshold set by manually editing the .cfg file would be
lost when saving changes using echocfg.

requested by Joe (1:249/303), Wilfred (2:280/464) and Michiel (2:280/5555) for
their little 3-node inter-zonal FTN:
"Zone Blind" option (enabled in echofg->Toggle Options or by adding a line
containing the string "ZONE_BLIND" to the sbbsecho.cfg file). This option
causes zones to be ignored (back to the 2D addresses of the 80s) when parsing
and generating SEEN-BY and PATH kludge lines in echomail messages.
Incremented version to 2.23.

memcpy calls and explicit setting of fields to 0) - this code is just bad.
The only functional change should be that the SBBSecho product code (0x12FF)
and major/minor version number is now added to headers of type 2+ packets
generated by SBBSecho. Type 2 and 2.2 packets will have just 0xff for the
product code and the SBBSecho major version number in the product "serial
number" field (as is the common practice). I guess everyone's using type 2+
packets these days? You don't get 5D addresses with 2+, but SBBSecho doesn't
really do anything with 5D addresses anyway. <shrug>

the "SYSOP_ALIAS" keyword in the sbbsecho.cfg file. e.g. can be set to
"Net Coordinator" with the line "SYSOP_ALIAS Net Coordinator". The default
value is "SYSOP" (case insensitive).

This is *likely* to break the Win32 build and even when the macros are
specified in xpdev, I doubt Microsoft has added support for the 'z' size
specifier used in smblib/smbadd.c we'll likely need a SIZE_T_SIZE macro
that is "z" on C99 systems and "ll" or "64" or whatever it is on Win32.

Or maybe a whole slew of complete SIZE_T macros since the 32/64 but thing
and the max file size thing may actually need the full format specification
to be in the macro... "zu" on C99 platforms and whatever magic Microsoft
needs there.

Updated help text/codes.
Eliminated unused "swap" option.

instead of "Notice".

Consider doing the same for all .h files.
Consider the meaning of sanity.

ala scfg

path detection.

bundle attachment netmail messages.

Added commad-line options to force text mode (-t) and stdio mode (-d).

(used to always do this, but some non-conforming echomail programs apparently
treat sole-carriage returns as soft-CRs and ignore/strip them).