added a CSS class for YUI button with a drop-down menu.

git-svn-id: https://hudson.dev.java.net/svn/hudson/trunk/hudson/main@31930 71c3de6d-444a-0410-be80-ed276b4c234a

war/resources/scripts/hudson-behavior.js

@@ -939,7 +939,13 @@ var hudsonRules = {
         e = null; // avoid memory leak
     },
 
-    "DIV.behavior-loading" : function(e) { e.style.display = 'none' }
+    "DIV.behavior-loading" : function(e) {
+        e.style.display = 'none';
+    },
+
+    ".button-with-dropdown" : function (e) {
+        new YAHOO.widget.Button(e, { type: "menu", menu: e.nextSibling });
+    }
 };
 
 function applyTooltip(e,text) {