Bugs
                                    ----

No priority bugs at this time


                                  Small Tasks
                                  -----------

* Add CHANGE-CLASS event testing to :gbbopen-test

* Improve define-tll-command SLIME support

* Add LispWorks "heavy-allocation" support to with-reading-saved/sent-objects


                                  Immediate
                                  ---------

* Add comparision-type compatibilty check in
  ADD-INSTANCE-TO-SPACE-INSTANCE-INTERNAL

* Add LispWorks 5.1 symeval-in-process support to Portable Threads

* Add SLIME REPL package setting to GBBopen commands


                                 Needed Soon
                                 -----------

* Worry about the effect on the storage for existing space instances when
  a unit-class definition is redefined with a changed dimensional-value
  specifications


                                 Needed Later
                                 ------------

find.lisp

 * optimize-pattern-element

   Change optimize-pattern-element and add-dimension-extent to handle negated
   regions (requires handling all dimensions in the pattern operator at once)
   to tile around the "hole".  Right now, add-dimension-extent must scan the
   entire area.

 * optimize-pattern

   Take another look at the #+is-this-needed-any-longer? clause.

storage.lisp

 * determine-2d-uniform-storage-regions

   Add smarter 2D-extent merging, for now we're only deleting obvious duplicates.

   Also, avoid full sweep on :infeasible pattern.


			     Future Enhancements
                             -------------------

space.lisp

 * add-instance-to-space-instance 
  
   Cache dimension-compatibility checks on space-instance after the first time
   an instance of a unit class is added.  Must be cleared if unit-class is
   redefined, however.