cleanup library and some basic tests. Includes, add guards to includes
diff --git a/library/md4.c b/library/md4.c
index 47f5c9c..d14390b 100644
--- a/library/md4.c
+++ b/library/md4.c
@@ -36,15 +36,20 @@
#include "polarssl/md4.h"
-#if defined(POLARSSL_FS_IO) || defined(POLARSSL_SELF_TEST)
+#include <string.h>
+
+#if defined(POLARSSL_FS_IO)
#include <stdio.h>
#endif
+#if defined(POLARSSL_SELF_TEST)
#if defined(POLARSSL_PLATFORM_C)
#include "polarssl/platform.h"
#else
+#include <stdio.h>
#define polarssl_printf printf
-#endif
+#endif /* POLARSSL_PLATFORM_C */
+#endif /* POLARSSL_SELF_TEST */
/* Implementation that should never be optimized out by the compiler */
static void polarssl_zeroize( void *v, size_t n ) {
