fix file headers & footers

Author: sjaeckel

bn_mp_decr.c

@@ -40,9 +40,8 @@ int mp_decr(mp_int *a)
    }
    return mp_sub_d(a, 1uL,a);
 }
-
-
 #endif
-/* ref:         \$Format:\%D$ */
-/* git commit:  \$Format:\%H$ */
-/* commit time: \$Format:\%ai$ */
+
+/* ref:         $Format:%D$ */
+/* git commit:  $Format:%H$ */
+/* commit time: $Format:%ai$ */

bn_mp_incr.c

@@ -35,8 +35,8 @@ int mp_incr(mp_int *a)
    }
    return mp_add_d(a, 1uL,a);
 }
-
 #endif
-/* ref:         \$Format:\%D$ */
-/* git commit:  \$Format:\%H$ */
-/* commit time: \$Format:\%ai$ */
+
+/* ref:         $Format:%D$ */
+/* git commit:  $Format:%H$ */
+/* commit time: $Format:%ai$ */

bn_mp_iseven.c

@@ -9,8 +9,7 @@
  * Michael Fromberger but has been written from scratch with
  * additional optimizations in place.
  *
- * The library is free for all purposes without any express
- * guarantee it works.
+ * SPDX-License-Identifier: Unlicense
  */
 
 int mp_iseven(const mp_int *a)

bn_mp_isodd.c

@@ -9,8 +9,7 @@
  * Michael Fromberger but has been written from scratch with
  * additional optimizations in place.
  *
- * The library is free for all purposes without any express
- * guarantee it works.
+ * SPDX-License-Identifier: Unlicense
  */
 
 int mp_isodd(const mp_int *a)