dgrid3d not available online, but docs still try to refer to it

[Hans-Bernhard B. <HBB...@t-...>]

Hello everyone,

I was just made aware that there's a little glitch with the demo URLs in 
gnuplot's documentation.  In particular, gnuplot.doc holds this:

^ <a href="http://www.gnuplot.info/demo/dgrid3d.html">
  dgrid3d.dem: dgrid3d demo.
^ </a>

But there is no dgrid3d.html on either www.gnuplot.info or gnuplot.sf.net.

So how to fix this: upload dgrid3d.html, or remove the link from 
gnuplot.doc?