[Dune] SuperLU installation notes

[Uli Sack]

Hi Dune!

I just needed to install SuperLU again and had a look at the 
installation notes on the dune website. I was surprised to see that they 
were originally written by me, and that was 4 years ago...

So I updated my local howTo a little according to todays working (where 
I used SuperLU4.2, the renamed enums put me off the newer release). 
However I have no idea for which file I have to prepare a patch in order 
to have these changes on the website.

cheers,Uli