autoconf usage : -DHAVE_GSL ?

[Peter Teuben]

> > Function 'main' -- standard autoconf trick.
> 
> Actually, I'd term it a "misuse". The fact that the library exists
> doesn't mean you should link against it. You should first AC_TRY_FUNC
> because it might already be in $LIBS.

actually, this still didn't work for me !  It still claimed it would not even
find main. If i link static (manually done), things look better, but basically,
i kept the stupid kludge in until i find something that actually works.

- peter