Include <stddef.h> in nettle-types.h, for size_t.

ChangeLog

+2013-05-20  Niels Möller  <nisse@lysator.liu.se>
+
+	* nettle-types.h: Include <stddef.h>, for size_t.
+
 2013-05-17  Niels Möller  <nisse@lysator.liu.se>
 
 	* macros.h (ROTL32, ROTL64): Avoid undefined behaviour for zero

nettle-types.h

@@ -23,9 +23,11 @@
 #ifndef NETTLE_TYPES_H
 #define NETTLE_TYPES_H
 
+/* For size_t */
+#include <stddef.h>
+
 /* Pretend these types always exists. Nettle doesn't use them. */
 #define _STDINT_HAVE_INT_FAST32_T 1
-
 #include "nettle-stdint.h"
 
 #ifdef __cplusplus