cleanup library and some basic tests. Includes, add guards to includes
diff --git a/include/polarssl/net.h b/include/polarssl/net.h
index d86732f..5f0b9ca 100644
--- a/include/polarssl/net.h
+++ b/include/polarssl/net.h
@@ -24,7 +24,7 @@
#ifndef POLARSSL_NET_H
#define POLARSSL_NET_H
-#include <string.h>
+#include <stddef.h>
#define POLARSSL_ERR_NET_UNKNOWN_HOST -0x0056 /**< Failed to get an IP address for the given hostname. */
#define POLARSSL_ERR_NET_SOCKET_FAILED -0x0042 /**< Failed to open a socket. */