stdlib fixes.

src/stdlib.h

@@ -1,8 +1,13 @@
 /*
  * stdlib.h replacement to replace malloc functions
+ *
+ * The intention is that no dependency to C library.  But since RSA
+ * routines uses malloc/free, we provide malloc and free.
+ *
+ * For GNU/Linux emulation, we can use C library.
  */
 
-typedef unsigned int size_t;
+typedef unsigned long int size_t;
 
 #include <stddef.h> /* NULL */
 
@@ -11,3 +16,9 @@ typedef unsigned int size_t;
 
 void *gnuk_malloc (size_t);
 void gnuk_free (void *);
+
+#ifdef GNU_LINUX_EMULATION
+long int random(void);
+void srandom(unsigned int seed);
+void exit(int status);
+#endif