- fixed missing stdlib.h and string.h includes everywhere
- removed a couple of unneeded stdlib.h and stdio.h includes

scheduler/semaphore.c

diff --git a/scheduler/semaphore.c b/scheduler/semaphore.c
index d329ec9..6fdcf70 100644
--- a/scheduler/semaphore.c
+++ b/scheduler/semaphore.c
@@ -5,6 +5,7 @@
  */
 
 #include <assert.h>
+#include <string.h>
 #include "winerror.h"
 #include "k32obj.h"
 #include "process.h"