cleanup library and some basic tests. Includes, add guards to includes
diff --git a/library/aesni.c b/library/aesni.c
index d4ec9ec..a235904 100644
--- a/library/aesni.c
+++ b/library/aesni.c
@@ -34,7 +34,8 @@
 #if defined(POLARSSL_AESNI_C)
 
 #include "polarssl/aesni.h"
-#include <stdio.h>
+
+#include <string.h>
 
 #if defined(POLARSSL_HAVE_X86_64)