display-buffer-in-previous-window existed before 24.4, but was not
in display-buffer-fallback-action
*** New display actions functions for `display-buffer':
-**** `display-buffer-in-previous-window' displays a buffer in a window
-previously showing that buffer.
-
**** `display-buffer-at-bottom' chooses or creates a window at the
bottom of the selected frame.
caller of `display-buffer' is ready to handle the case of not displaying
the buffer in a window.
+*** `display-buffer-in-previous-window' is now a member of
+`display-buffer-fallback-action'.
+
** Lisp evaluation
*** `eval-defun' on an already defined defcustom calls the :set function,