prefix errors with name of program

[Dan Jacobson]

Today again lots of head scratching because bash and perl don't prefix
their error messages with a "bash:" or a "perl:", so bash scripts with
bits of perl often take deep scrutinization to figure out what the
problem was.

It's as if each author never expected any embedding of scripts. Make
might call bash might call perl.  Make says "make:", but highfalutin
bash and perl act like "why of course, were you expecting to be
running something else?"