Replace NofibUtils.hs with package

Make NofibUtils a package and get rid of the symlinks.

It caused a neverending string of frustration on windows.

I did this by making it into a package that is unconditionally used as dependency for all benchmarks.

I've hacked the make build system to also include the file. It's not pretty but "works" best I can tell. But it still leaves the make build system broken because of the other dependencies.