Store the global shell, progman and taskman windows in the server
(based on a patch by Martin Fuchs).

diff --git a/server/request.h b/server/request.h
index 8f9f9d6..a0287ad 100644
--- a/server/request.h
+++ b/server/request.h
@@ -281,6 +281,7 @@
 DECL_HANDLER(get_next_hook);
 DECL_HANDLER(set_clipboard_info);
 DECL_HANDLER(open_token);
+DECL_HANDLER(set_global_windows);
 
 #ifdef WANT_REQUEST_HANDLERS
 
@@ -465,6 +466,7 @@
     (req_handler)req_get_next_hook,
     (req_handler)req_set_clipboard_info,
     (req_handler)req_open_token,
+    (req_handler)req_set_global_windows,
 };
 #endif  /* WANT_REQUEST_HANDLERS */