anchor.diff:  (defshortcut (#\b) (banish))
   (defshortcut (#\') (finder))
   (defshortcut (#\f) (fullscreen))
  +(defshortcut (#\g) (group))
  +(defshortcut (#\u) (ungroup))
   (defshortcut (:shift #\f) (fullscreen :pinned-p t))
   (defshortcut (#\.) (center))
   (defshortcut (:shift #\.) (center))
  
positive.code:   (xlib:grab-keyboard *root*)
    (unwind-protect (recdo *windows* #'focus :key #'xclass :matcher #'in-matcher)
      (xlib:ungrab-keyboard *display*)))
  
  (defun banish ()
    "Banish mouse pointer."
  
negative.code:              (rplacd ,asc #',fn)
               (push (cons ,sc #',fn) *shortcuts*))))))
  
  (defun %group (window char) (setf (getf (xlib:window-plist window) :group) char))
  (defun pinned-p (window) (getf (xlib:window-plist window) :pinned))
  (defun pin (window) (setf (getf (xlib:window-plist window) :pinned) t))
  (defun unpin (window) (remf (xlib:window-plist window) :pinned))
  