include: add some missing licence stuff to header files

It's mostly wrappers for compatibility and another trivial stuff etc.
Let's keep it as public domain to make it more portable to LGPL, GPL
and BSD code.

Signed-off-by: Karel Zak <kzak@redhat.com>
CC: Sami Kerola <kerolasa@iki.fi>
CC: Ruediger Meier <ruediger.meier@ga-group.nl>

include/c.h

@@ -1,7 +1,9 @@
 /*
  * Fundamental C definitions.
+ *
+ * No copyright is claimed.  This code is in the public domain; do with
+ * it what you wish.
  */
-
 #ifndef UTIL_LINUX_C_H
 #define UTIL_LINUX_C_H
 

include/monotonic.h

@@ -1,3 +1,7 @@
+/*
+ * No copyright is claimed.  This code is in the public domain; do with
+ * it what you wish.
+ */
 #ifndef UTIL_LINUX_MONOTONIC_H
 #define UTIL_LINUX_MONOTONIC_H
 

include/namespace.h

@@ -1,4 +1,10 @@
-/* Compat code so unshare and setns can be used with older libcs */
+
+/*
+ * No copyright is claimed.  This code is in the public domain; do with
+ * it what you wish.
+ *
+ * Compat code so unshare and setns can be used with older libcs
+ */
 #ifndef UTIL_LINUX_NAMESPACE_H
 # define UTIL_LINUX_NAMESPACE_H
 

lib/mangle.c

@@ -1,7 +1,8 @@
 /*
  * Functions for \oct encoding used in mtab/fstab/swaps/etc.
  *
- * Based on code from mount(8).
+ * No copyright is claimed.  This code is in the public domain; do with
+ * it what you wish.
  *
  * Copyright (C) 2010 Karel Zak <kzak@redhat.com>
  */

lib/monotonic.c

@@ -1,6 +1,9 @@
 /*
  * Please, don't add this file to libcommon because clock_gettime() requires
  * -lrt on systems with old libc.
+ *
+ * No copyright is claimed.  This code is in the public domain; do with
+ * it what you wish.
  */
 #include <time.h>
 #include <signal.h>