Changes to PCL available (STRUCTURE-CLASS & bug fixes)

[Simon Leinen <simon@lia.di.epfl.ch>]

I have made a few changes to the PCL that CMU CL uses:

* applied the patches that were have been put on
  parcftp.Xerox.COM:/pub/pcl/patches-for-pcl-rev-4b on March 5

* adapted and integrated structure.lisp

Now methods can be defined on DEFSTRUCT types!

If you want to pick up the changes, they can be FTPed anonymously from
liasun3.epfl.ch:/pub/lisp/cmucl/pcl-patch-1992-03-18.Z.

Have fun,
-- 
Simon.