Reorder copyright messages in cjpeg/djpeg/jpegtran

Place the authors in the following order:
* libjpeg-turbo authors (2009-) in descending order of the date of their
  most recent contribution to the project, then in ascending order of
  the date of their first contribution to the project
* Upstream authors in descending order of the date of the first
  inclusion of their code (this indicates that their code serves as the
  foundation of this code.)

This also adds Siarhei to the author list, since he contributed ARM SIMD
code both as a Nokia employee and more recently as an independent
developer.

jversion.h

@@ -26,13 +26,23 @@
 
 #endif
 
-#define JCOPYRIGHT      "Copyright (C) 1991-2016 Thomas G. Lane, Guido Vollbeding\n" \
-                        "Copyright (C) 1999-2006 MIYASAKA Masaru\n" \
-                        "Copyright (C) 2009 Pierre Ossman for Cendio AB\n" \
-                        "Copyright (C) 2009-2016 D. R. Commander\n" \
-                        "Copyright (C) 2009-2011 Nokia Corporation and/or its subsidiary(-ies)\n" \
+/*
+ * NOTE: It is our convention to place the authors in the following order:
+ * - libjpeg-turbo authors (2009-) in descending order of the date of their
+ *   most recent contribution to the project, then in ascending order of the
+ *   date of their first contribution to the project
+ * - Upstream authors in descending order of the date of the first inclusion of
+ *   their code
+ */
+
+#define JCOPYRIGHT      "Copyright (C) 2009-2016 D. R. Commander\n" \
+                        "Copyright (C) 2011-2016 Siarhei Siamashka\n" \
+                        "Copyright (C) 2015-2016 Matthieu Darbois\n" \
                         "Copyright (C) 2013-2014 MIPS Technologies, Inc.\n" \
                         "Copyright (C) 2013 Linaro Limited\n" \
-                        "Copyright (C) 2015 Matthieu Darbois"
+                        "Copyright (C) 2009-2011 Nokia Corporation and/or its subsidiary(-ies)\n" \
+                        "Copyright (C) 2009 Pierre Ossman for Cendio AB\n" \
+                        "Copyright (C) 1999-2006 MIYASAKA Masaru\n" \
+                        "Copyright (C) 1991-2016 Thomas G. Lane, Guido Vollbeding" \
 
 #define JCOPYRIGHT_SHORT "Copyright (C) 1991-2016 The libjpeg-turbo Project and many others"