Stop mouseover on the palette items in the customize toolbar dialog.

toolkit/content/widgets/toolbar.xml

@@ -94,5 +94,6 @@
 
   <binding id="toolbarseparator" extends="chrome://global/content/widgets/toolbar.xml#toolbar-base"/>
 
+  <binding id="toolbarpaletteitem" extends="xul:button"/>
 </bindings>          
 

toolkit/content/xul.css

@@ -208,6 +208,10 @@ toolbarseparator {
   -moz-binding: url("chrome://global/content/widgets/toolbar.xml#toolbarseparator");
 }
 
+toolbarpaletteitem {
+  -moz-binding: url("chrome://global/content/widgets/toolbar.xml#toolbarpaletteitem");
+}
+
 /********* menubar ***********/
 
 menubar {