ox/ox-html: Use a language agnostic and more neutral default creator

* lisp/ox-html.el (org-html-creator-string): Change default value.
* lisp/ox.el (org-export-creator-string): Change default value.

lisp/ox-html.el

@@ -1052,9 +1052,9 @@ like that: \"%%\"."
   :type 'string)
 
 (defcustom org-html-creator-string
-  (format "Generated by <a href=\"http://orgmode.org\">Org</a> mode %s in <a href=\"http://www.gnu.org/software/emacs/\">Emacs</a> %s."
-	  (if (fboundp 'org-version) (org-version) "(Unknown)")
-	  emacs-version)
+  (format "<a href=\"http://www.gnu.org/software/emacs/\">Emacs</a> %s (<a href=\"http://orgmode.org\">Org</a> mode %s)"
+	  emacs-version
+	  (if (fboundp 'org-version) (org-version) "unknown version"))
   "Information about the creator of the HTML document.
 This option can also be set on with the CREATOR keyword."
   :group 'org-export-html

lisp/ox.el

@@ -385,9 +385,9 @@ string."
 	  (const :tag "No format string" nil)))
 
 (defcustom org-export-creator-string
-  (format "Generated by Org mode %s in Emacs %s."
-	  (if (fboundp 'org-version) (org-version) "(Unknown)")
-	  emacs-version)
+  (format "Emacs %s (Org mode %s)"
+	  emacs-version
+	  (if (fboundp 'org-version) (org-version) "unknown version"))
   "Information about the creator of the document.
 This option can also be set on with the CREATOR keyword."
   :group 'org-export-general