Update Mode Line

[Eugene C. Ciccarelli <ECC at MIT-AI>]

In ZWEI in Remote-File 7.0, LMFILE-Remote 15.2, MIT-Specific 7.1,
System 85.45, ZMail 44.3, microcode 123, 60.45Hz, on Lisp Machine Six:

Mode line's package is not getting updated:
1. Create buffer FOO.
2. Insert the following mode line:
;;; -*-Package:USER; Base:10.; Mode:Lisp-*-
3. M-X Reparse Mode Line.  (Maybe not needed.)
4. M-X Set Package to SI (for example).
5. M-X Update Mode Line.  The mode line will redisplay but still
say:
;;; -*-Package:USER; Base:10.; Mode:Lisp-*-