cleanup library and some basic tests. Includes, add guards to includes
diff --git a/include/polarssl/oid.h b/include/polarssl/oid.h
index 309d8c5..497eac8 100644
--- a/include/polarssl/oid.h
+++ b/include/polarssl/oid.h
@@ -24,14 +24,17 @@
#ifndef POLARSSL_OID_H
#define POLARSSL_OID_H
-#include <string.h>
#if !defined(POLARSSL_CONFIG_FILE)
#include "config.h"
#else
#include POLARSSL_CONFIG_FILE
#endif
+
#include "asn1.h"
#include "pk.h"
+
+#include <stddef.h>
+
#if defined(POLARSSL_CIPHER_C)
#include "cipher.h"
#endif