bug#19989: 25.0.50; Build instructions on Windows

[martin rudalics]

> It depends on which tools you use to unpack.  If the tools allow you
> to say "do not override with older files", the probability of errors
> is greatly reduced.

The tools say that.  The problematic component is the person using them.

>> You have a well maintained code base and much superior knowledge.
>> Starting from scratch is not comparable to that.
>
> I, too, started from scratch at some point ;-)

So all I can hope is that one day all your machines, backups and notes
crash simultaneously, you forget everything you've done before in this
area, have to start from scratch again and will publish here what you've
done to produce a working environment :-(

martin