T and NIL.

[George J. Carrette <GJC at MIT-MC>]

1. Right, not much VAX-NIL code written in LISP depends on this T and NIL issue.
2. Right, no query-replace was needed, no subtle bugs lurking due to this.
   I did make a readtable for Macsyma so that NIL read in as ().
3. Here I meant that the "T and NIL" thing is not an important
   TRANSPORTABILITY issue. Code which does not depend on the overloading
   will indeed run. But building the overloading into NIL at this point
   will cost something. I'm not sure it is worth it.