Fix #525: sbang handles symlinks & directories properly.
Fix #525: sbang handles symlinks & directories properly.

matthiasdiener/spack,iulian787/spack,LLNL/spack,TheTimmy/spack,LLNL/spack,lgarren/spack,skosukhin/spack,EmreAtes/spack,lgarren/spack,tmerrick1/spack,LLNL/spack,tmerrick1/spack,mfherbst/spack,iulian787/spack,skosukhin/spack,mfherbst/spack,tmerrick1/spack,matthiasdiener/spack,krafczyk/spack,lgarren/spack,EmreAtes/spack,iulian787/spack,TheTimmy/spack,krafczyk/spack,tmerrick1/spack,EmreAtes/spack,krafczyk/spack,skosukhin/spack,mfherbst/spack,lgarren/spack,EmreAtes/spack,mfherbst/spack,iulian787/spack,LLNL/spack,matthiasdiener/spack,krafczyk/spack,TheTimmy/spack,TheTimmy/spack,lgarren/spack,krafczyk/spack,skosukhin/spack,LLNL/spack,iulian787/spack,TheTimmy/spack,EmreAtes/spack,tmerrick1/spack,skosukhin/spack,matthiasdiener/spack,matthiasdiener/spack,mfherbst/spack