[tldoc] doc update for windows %systemdrive%

[Karl Berry]

    -        \url{http://pascal.brachet.club.fr/texmaker/}.
    +        \url{http://www.xm1math.net/texmaker/}.

Thanks.

I wish I'd thought of removing that whole list from the manual.  It's
nothing that needs to be enshrined there; pointing to a web page would
be better.  So it goes.  Maybe next year.