Thanks to Mikael Djurfeldt for a bugreport which led to the

Thanks to Mikael Djurfeldt for a bugreport which led to the
following changes:

* slib.scm (%system-define): Removed.

(define): Changed to use define-private instead of
%system-define.

* boot-9.scm (define-private): Undid my changes from 2002-11-16
until Guile supports hygienic macros.