[petsc-dev] --with-shared-libraries=1 is a happy camper if it ends up using a static linker

[Barry Smith]

   Hmm,  when someone explicitly sets --with-shared-libraries=1  I think they would be rather upset if configure ends up using ar and static libraries because it could not find options to build shared libraries.

    Yet that is what happens now!

   Could someone add support so that if a user specifically requests  --with-shared-libraries=1 configure barfs with a nice error message if it cannot find any? 

    I think it is a trivial code change but does require the snippet go in exactly the right place which I cannot determine 

   Thanks

    Barry