Allow non-standard location for Perl interpreter throughout

[m.hadfield]

The sfmakedepend script file starts with:

#!/usr/bin/perl -w

This fails on one of my systems, where perl is not installed in /usr/bin. One solution is to use the form in cpp_clean, ie:

#!/usr/bin/env perl

(This was adopted some time ago at my suggestion, I think.)

There is a minor problem with this: it prevents the use of switches like "-w", owing to limitations in the Unix interpreter. There are various ways of working around this, but they are all far too complicated for me to understand:

​http://perldoc.perl.org/perlrun.html

However I don't think the "-w" switch (enable warnings) is needed in production code like this. Sfmakedepend works fine without it.

So, my suggestion is that "#!/usr/bin/perl" be replaced with "#!/usr/bin/env perl" in all scripts and that any command-line options be omitted. The only files I can find affected by this are:

ROMS/Bin/sfmakedepend ROMS/Bin/substitute