New version of PCL for Genera

[Gregor.pa@Xerox.COM]

There is a new version of PCL on parcvax.xerox.com.  This version runs
in Symbolics Releease 7.0 (Genera).  It does not work in Franz 1.4 yet,
but I am working on that, I don't know about the others yet.

NOTE: after you get the files, read 3600-notes.txt, in order to use this
version of PCL you must load the file rel-7-patches first.