Also controlled via [modem] CallerID key in svdm.ini fiile.
Reports the connected IP address between the first and second RING result.
Required a fix to reset the ringcount to 0 upon new connection.

Simplified the AT command parsing logic a bit.

This sets the stage for "Caller-ID" support and IP/host filtering (before
sending a "RING" result and requiring an auto-answer or host/BBS software to
send "ATA").

Likely fix for the user.dat open file descriptor leak:
If js_CreateUserObject(cx,parent,cfg,"name",...) is called multiple times
(e.g. before login and after login), the successive calls will reuse the
previously allocated JS object and allocated private data memory. However, the
private data memory (which includes the descriptor of an open user.dat file,
if it has been opened), was always zeroed, even if it was being reused. This
would leak open file descriptor.

So any (pre)login scripts or web scripts that use the "user" object (which
is all zeroed-out before login) and then allows a user to subsequently login,
would leak a file descriptor.

by default, client.ini in the current working directory.
Configurable filename via ClientFile key in the root section of svdm.ini.

Re-init the UART struct in the init routine to avoid confusion when making .ini file changes with older NTVDMs (including NTVDMx64) which don't re-load the VDDs for every invocation.

Added undocumented experimental options -I and -O to enable DOS input and output interception modes in sbbsexec (e.g. to be used possibly with '-h'). Also -M to specify sbbsexec mode value by number (e.g. 3 to enable DOS Input/Output redir).

Added '-n' option to specify node number (probably no real value/need).

Safe string formatting.

When listening, the address family cannot be PF_UNSPEC, so default to PF_INET (IPv4), when not specified.
Not sure why we're setting ai_flags to PF_UNSPEC (copied from syncterm) - that's just 0, but otherwise the PF_ and AI_ flags are not compatible.
Don't set the ai_flags to anything here since they don't seem to change the behavior.

Fix a corner case where an invalid command-mode escape sequence (e.g. "+.+.+") could've been interpreted as valid.

More case-insensitivity in parsing special "number" values (e.g. 'L' for last number).

Default to Telnet mode (not Raw TCP).
Default to unspecific address family (not IPv4).
Case-insensitive "-telnet" and "-raw" option recognition.

To (re)generate git_branch.h and git_hash.h every build

svdm -V and "ATi1" output.

To be more consistent with other Synchronet project and solution files.

So it can be reused for other projects more easily

Set sbbs_hungup event state correctly based on initial online state (i.e. FALSE if already connected/online).

Allow BusyNotice (string) to be configurable via .ini file.

Support specifying an additional or alternate .ini file to read using -c<fname> option.

Support [sockopts] (socket options) settings in ini file

CamelCase the ini key names

When the 'number' property of an instance of User was incremented beyond the last user, the call to fgetuserdat() on subsequent property 'get' operation would fail and zero-out the user structure (including the user number). This resulted in an infinite loop in load/birthdays.js where the user number would go from lastuser to 1 in one operation (u.number++).

Reported by DesotoFireflite (VALHALLA)

Build using WinXP-compatible toolset.

sbbsctrl build failed, it needs another winsock header. <sigh>

Oh what a rabbit hole this has been.

And create IPv4AddressToStr(), a wrapper for inet_ntop (or inet_ntoa, when inet_ntop isn't available).

Fixes CI and nightly build.

e.g. AT&W writes the current settings to the [modem] section.

Use inet_ntop and inet_pton instead.

Use 32-bit arguments and return values for IPv4 addressess for all target platforms (ulong is 64-bit on LP64, e.g. Linux-x64, targets).

Have a service (e.g. imapservice.js) that logs errors that you'd rather not fill your error.log file with? Set that service's "LowestLogLevel" to "Warning" in your services.ini file ("lower" means "more severe" when it comes to log levels, so this would set the maximum severity to Warning).

Some responding programs will automatically remove the trailing white-space from subject when replying and that would mess up the subject-linkage-by-CRC. So let's just ignore trailing whitespace in the first place.

Reducing log output (lowering log level of line 437 from LOG_INFO to LOG_DEBUG) highlighted an issue with Telix stopping RX. That was fixed by checking RTS in input_thread(). Qmodem needs RTS checked when writing the MCR.

This improved RTS support has been tested with Telix, Qmodem, Telemate, and Banacom at full data rates.

New option to disable local screen display for door programs: sets the 'Screen' value appropriately in door.sys or pcboard.sys drop files and on Windows, doesn't create a new console window.

Also, now parsing the DOSXTRN.ERR file created by the latest/greatest dosxtrn.exe when failing to execute the child/DOS program and log the parsed error details (errno value and description), helpful in debugging the reason why a DOS program may not have been successfully executed by DOSXTRN.