Import mx's StringUtil.substitute() into our own StringUtil, as it's annoying

to have two StringUtils.


git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@4475 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/as/com/threerings/util/StringUtil.as

@@ -91,6 +91,14 @@ public class StringUtil
         return str;
     }
 
+    /**
+     * Substitute "{n}" tokens for the corresponding passed-in arguments.
+     */
+    public static function substitute (str :String, ... args) :String
+    {
+        return mx.utils.StringUtil.substitute(str, args);
+    }
+
     /**
      * Utility function that strips whitespace from the ends of a String.
      */