Implement fullscreen mode (Mod1+f)

include/util.h

@@ -8,10 +8,16 @@
  * See file LICENSE for license information.
  *
  */
+#include <xcb/xcb.h>
+
+#include "data.h"
+
 #ifndef _UTIL_H
 #define _UTIL_H
 
 void start_application(const char *command);
 void check_error(xcb_connection_t *connection, xcb_void_cookie_t cookie, char *err_message);
+void set_focus(xcb_connection_t *conn, Client *client);
+void toggle_fullscreen(xcb_connection_t *conn, Client *client);
 
 #endif