- Fix headers to include less or smaller header files.
- Fix header and source files to include missing header files to avoid
  warnings and errors.

diff --git a/include/struct32.h b/include/struct32.h
index f714588..a239ece 100644
--- a/include/struct32.h
+++ b/include/struct32.h
@@ -3,6 +3,7 @@
 #define __WINE__STRUCT32_H
 
 #include "winbase.h"
+#include "wine/winuser16.h"
 #include "queue.h"
 
 extern void STRUCT32_MINMAXINFO32to16( const MINMAXINFO32*, MINMAXINFO16* );