Bug 164466 Remove unused debug window pref

patch by walk84@yahoo.com r=caillon sr=bryner

suite/common/pref/pref-debug.xul

@@ -30,7 +30,7 @@
 
   <script type="application/x-javascript">
   <![CDATA[
-    var _elementIDs = ["nglayoutDebugWindow", "nglayoutUseNativePrintDialog", "printUseGlobalPrintSettings",
+    var _elementIDs = ["nglayoutUseNativePrintDialog", "printUseGlobalPrintSettings",
                        "debugXULBoxes", "browserDOMWindowDumpEnabled", 
                        "javascriptOptionsStrict", "javascriptOptionsShowInConsole", 
                        "nglayoutDebugUseXBLForms",
@@ -50,8 +50,6 @@
         <row align="center">
           <checkbox id="debugXULBoxes" label="&debugXULBox.label;"
                     prefstring="xul.debug.box"/>
-          <checkbox id="nglayoutDebugWindow" label="&debugWindow.label;"
-                    prefstring="nglayout.widget.debugWindow"/>
         </row>
       </rows>
     </grid>

suite/locales/en-US/chrome/common/pref/pref-debug.dtd

@@ -14,7 +14,6 @@
 
 <!-- Debug: Turn on gfx-rendered widgets -->
 <!ENTITY widgetRendering.label "Rendering">
-<!ENTITY debugWindow.label "debug window">
 <!ENTITY debugXULBox.label "debug XUL boxes">
 <!ENTITY useNativePrintDialog.label "Use Native Print Dialog (where supported)">
 <!ENTITY printUseGlobalPrintSettings.label "Use Global Print Settings">