Change procedures MOVE-THING, MOVE-THING-SAVING-POINT, MARK-THING, and

Change procedures MOVE-THING, MOVE-THING-SAVING-POINT, MARK-THING, and
KILL-THING to take an additional argument that specifies the limit
behavior of the motion procedure.  This is needed because these
procedures were being used in contexts that required different
behavior -- and because they didn't supply it, some of the usages were
incorrect.