Include string.h.

Rev: src/nettle/testsuite/testutils.c:1.4
Rev: src/nettle/twofish.c:1.4

testsuite/testutils.c

@@ -4,6 +4,7 @@
 
 #include <ctype.h>
 #include <stdlib.h>
+#include <string.h>
 
 int
 decode_hex(uint8_t *dst, const char *hex)

twofish.c

@@ -36,6 +36,7 @@
 #include "macros.h"
 
 #include <assert.h>
+#include <string.h>
 
 /* Bitwise rotations on 32-bit words.  These are defined as macros that
  * evaluate their argument twice, so do not apply to any expressions with