Better but temp icond for the DOM panel

Author: janodvarko

chrome/skin/classic/shared/tool-dom.png

@@ -36,7 +36,7 @@ const DomPanel = Class(
 
   label: Locale.$STR("dom.panel.title"),
   tooltip: Locale.$STR("dom.panel.tip"),
-  icon: "./icon-16.png",
+  icon: "chrome://firebug/skin/tool-dom.png",
   url: "./dom/dom.html",
   searchable: true,