Upgrade to hharte's 4.01

The update is significant to incorporate the reversed fixes for 4.01! Thanks to hharte!
https://github.com/hharte/MS-DOS

I've been able to build this from both MS-DOS 5 & Win32.

SRCSTACK includes the boot stack fix, and is suitable for building under MS-DOS
dos401_win32 has the same sources, but win32 friendly makefiles that allows for building through MS-DOS player ( http://takeda-toshiya.my.coocan.jp/msdos/ ), along with some native tools I've found along the way.

And finally a 1.44MB floppy image. It doesn't have the right labels so select isn't happy (SELECT MENU). But it looks sane now!

More so new build cross from Win32/Win64

Nothing much in the repo changed, this is a bigger update for my cross build tools from Win32/Win64 for building MS-DOS 4.00. I've switched the majority to this MASM386 I found somewhere (can't remember) as it's a Win32 native version, so no overhead, along with using the C/C++ compiler 8.00c which is also native Win32 greatly reducing the need for MS-DOS Player and greatly speeding up cross compilation.

On my machine it takes about two minutes to build the entire thing.

Now can boot from hard disk!

Thanks to Michal Necasek the boot stack bug was 'patched' to at least allow booting on Qemu & VMware!

Probably many other machines as well
https://www.os2museum.com/wp/how-not-to-release-historic-source-code/comment-page-1/#comment-381416

and care of Licca a fix from John Elliott that addresses a bug in debug that is in in every version from 2.0 onward and affects CALL 5

I'll also attach a source zip suitable for building withing dosbox or ms-dos - Even DOS4 can rebuild itself!

Compiled it!

And it boots too!

Probably need to figure out a better fix for the weird � chars.