cleanup library and some basic tests. Includes, add guards to includes
diff --git a/library/bignum.c b/library/bignum.c
index 0eb95ee..91cbf29 100644
--- a/library/bignum.c
+++ b/library/bignum.c
@@ -38,16 +38,18 @@
#include "polarssl/bignum.h"
#include "polarssl/bn_mul.h"
+#include <string.h>
+
#if defined(POLARSSL_PLATFORM_C)
#include "polarssl/platform.h"
#else
+#include <stdio.h>
+#include <stdlib.h>
#define polarssl_printf printf
#define polarssl_malloc malloc
#define polarssl_free free
#endif
-#include <stdlib.h>
-
/* Implementation that should never be optimized out by the compiler */
static void polarssl_zeroize( void *v, size_t n ) {
volatile unsigned char *p = v; while( n-- ) *p++ = 0;