bug fix for 'insert' in opus 38.50

[Dorab Patel <patel@UCLA-LOCUS>]

The function 'insert' in Opus 38.50 does not perform as advertised in 
the manual if the last argument is non-nil (i.e. if no duplicates are allowed.
It still insists on putting the duplicate element into the list. The
fix is in /usr/lib/lisp/common2.l. Just change the default setting
of the 'comparefn' to that given below instead of 
(function alphalessp). Here is an excerpt from the modified file.


  [.....]
(def insert
     (lambda (x l comparefn nodups)
      (cond ((null l) (list x))
            ((atom l)
             (error "an atom, can't be inserted into" l))
            (t (cond
                ((null comparefn) (setq comparefn 
					(function
					 (lambda (x y) 
						 (or (alphalessp x y) 
						     (equal x y)))))))
               (prog (l1 n n1 y)
                     (setq l1 l)
                     (setq n (length l))
                a    (setq n1 (/ (add1 n) 2))
                     (setq y (Cnth l1 n1))
		     [..........]