Use string width to center headline in ascii export.

lisp/org-exp.el

@@ -2063,7 +2063,8 @@ underlined headlines.  The default is 3."
     (if org-export-with-toc
 	(progn
 	  (push (concat (nth 3 lang-words) "\n") thetoc)
-	  (push (concat (make-string (length (nth 3 lang-words)) ?=) "\n") thetoc)
+	  (push (concat (make-string (string-width (nth 3 lang-words)) ?=)
+			"\n") thetoc)
 	  (mapc '(lambda (line)
 		   (if (string-match org-todo-line-regexp
 				     line)
@@ -2237,7 +2238,7 @@ underlined headlines.  The default is 3."
 
 (defun org-insert-centered (s &optional underline)
   "Insert the string S centered and underline it with character UNDERLINE."
-  (let ((ind (max (/ (- 80 (string-width s)) 2) 0)))
+  (let ((ind (max (/ (- fill-column (string-width s)) 2) 0)))
     (insert (make-string ind ?\ ) s "\n")
     (if underline
 	(insert (make-string ind ?\ )
@@ -3198,6 +3199,8 @@ lang=\"%s\" xml:lang=\"%s\">
 	    (insert "<p class=\"date\"> "
 		    (nth 2 lang-words) ": "
 		    date "</p>\n"))
+	  (insert (format "<p>HTML generated by org-mode %s in emacs %s<\p>\n"
+			  org-version emacs-major-version))
 	  (insert "</div>"))
 
 	(if org-export-html-with-timestamp