- nsf.c: * ensure that explicit per-object-mixins are kept at the front in "info heritage" order and in "info precedence" when classes are added as POMs and PCMs * extended regression test
- nsf.c: * added NsfClassListNoDup() to allow just single inserts * added NsfClassListPrint() for debugging * info heritage returns no duplicates * added prototype for NsfNoCurrentObjectError() * report "no current object" when no object is passed to a method. * code cleanup - extended regression test