Moves more stuff from windows.h.
- include/winuser.h - interface relevant to user32.spec
- include/wine/winuser16.h - the old 16 bit interface (internal use)
- include/winbase.h - some minor updates to keep things coherent.
- Lot of other files made to include wine/winuser16.h, which is no
  longer included from windows.h

diff --git a/controls/desktop.c b/controls/desktop.c
index 73baa5a..bb6b64d 100644
--- a/controls/desktop.c
+++ b/controls/desktop.c
@@ -10,6 +10,7 @@
 #include "win.h"
 #include "desktop.h"
 #include "heap.h"
+#include "wine/winuser16.h"
 
 
 /***********************************************************************