Bug 344545 DOM Inspector 1.8.1b1 Leak (dom.js)

patch by comrade693+bmo@gmail.com r=db48x sr=neil

extensions/inspector/resources/content/viewers/dom/dom.js

@@ -67,6 +67,7 @@ function DOMViewer_initialize()
 function DOMViewer_destroy()
 {
   PrefUtils.removeObserver("inspector", PrefChangeObserver);
+  viewer.removeClickListeners();
   viewer = null;
 }