Update Mode Line

[David L. Andre <DLA at SCRC-TENEX>]

    Date: 27 May 1982 16:19-EDT
    From: 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-*-

This happens in 210 too, if you don't opt to update the mode line in Set
Package.  Maybe we should flush packages altogether.