i3bar: Correctly handle removal of tray clients

i3bar/include/trayclients.h

@@ -0,0 +1,24 @@
+/*
+ * i3bar - an xcb-based status- and ws-bar for i3
+ *
+ * © 2010-2011 Axel Wagner and contributors
+ *
+ * See file LICNSE for license information
+ *
+ */
+#ifndef TRAYCLIENT_H_
+#define TRAYCLIENT_H_
+
+#include "common.h"
+
+typedef struct trayclient trayclient;
+
+TAILQ_HEAD(tc_head, trayclient);
+
+struct trayclient {
+    xcb_window_t       win;         /* The window ID of the tray client */
+
+    TAILQ_ENTRY(trayclient) tailq;  /* Pointer for the TAILQ-Macro */
+};
+
+#endif