fix missing includes in clients/window.h and clients/wayland-glib.h
diff --git a/clients/window.h b/clients/window.h
index de7ccce..7b96704 100644
--- a/clients/window.h
+++ b/clients/window.h
@@ -23,6 +23,9 @@
 #ifndef _WINDOW_H_
 #define _WINDOW_H_
 
+#include <glib.h>
+#include <wayland-client.h>
+
 struct window;
 
 struct rectangle {