move strndup to libi3

include/util.h

@@ -139,16 +139,4 @@ void *memmem(const void *l, size_t l_len, const void *s, size_t s_len);
 
 #endif
 
-#if defined(__APPLE__)
-
-/*
- * Taken from FreeBSD
- * Returns a pointer to a new string which is a duplicate of the
- * string, but only copies at most n characters.
- *
- */
-char *strndup(const char *str, size_t n);
-
-#endif
-
 #endif