Backport commit 26d58f0c5 from Emacs

; Standardize license notices
26d58f0c5865c9132e2fc559e061ef704a086d30
Glenn Morris
Fri Sep 29 12:49:19 2017 -0400

lisp/ob-vala.el

@@ -8,6 +8,8 @@
 
 ;;; License:
 
+;; This file is part of GNU Emacs.
+
 ;; GNU Emacs is free software: you can redistribute it and/or modify
 ;; it under the terms of the GNU General Public License as published by
 ;; the Free Software Foundation, either version 3 of the License, or

lisp/org-duration.el

@@ -1,22 +1,24 @@
 ;;; org-duration.el --- Library handling durations   -*- lexical-binding: t; -*-
 
-;; Copyright (C) 2017  Free Software Foundation, Inc.
+;; Copyright (C) 2017 Free Software Foundation, Inc.
 
 ;; Author: Nicolas Goaziou <mail@nicolasgoaziou.fr>
 ;; Keywords: outlines, hypermedia, calendar, wp
 
-;; This program is free software; you can redistribute it and/or modify
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs is free software: you can redistribute it and/or modify
 ;; it under the terms of the GNU General Public License as published by
 ;; the Free Software Foundation, either version 3 of the License, or
 ;; (at your option) any later version.
 
-;; This program is distributed in the hope that it will be useful,
+;; GNU Emacs is distributed in the hope that it will be useful,
 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 ;; GNU General Public License for more details.
 
 ;; You should have received a copy of the GNU General Public License
-;; along with this program.  If not, see <https://www.gnu.org/licenses/>.
+;; along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
 
 ;;; Commentary: