restricted JFN's

[Dave Touretzky at CMU-10A]

I agree with Feinberg's suggestion, except I think the default should be
to not restrict the JFNs.  I find the @INFO FILES command a quick and
useful check of what a program's been up to; restricting that
information (or making it harder to get at than simply typing ^C and
 @INFO FILES) is counterproductive to 99% of MacLisp users.  Sure, there
might be a subfork hacker out there who is so paranoid he wants to
protect his JFNs, but if he's that tight-assed he can certainly make
the effort to set the RESTRICT-JFN switch to T or do (SSTATUS RJFN T)
or perform whatever other magic incantation is necessary.