Add includes to make headers self-contained

src/client/secure.h

@@ -34,6 +34,8 @@
 #ifndef SECURE_H
 #define SECURE_H
 
+#include <stddef.h>
+
 extern size_t save_input(char *);
 extern size_t seen_input(char *);
 extern void forget_input(size_t);

src/lib/lwp/lwpint.h

@@ -36,6 +36,7 @@
 #define LWPINT_H
 
 #include <signal.h>
+#include <time.h>
 #include <ucontext.h>
 
 #include "misc.h"