Added endsWith().

git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@4226 542714f4-19e9-0310-aa3c-eee0fc999fb1

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

@@ -9,6 +9,15 @@ public class StringUtil
         return (str == null) || (str.search("\\S") == -1);
     }
 
+    /**
+     * Does the specified string end with the specified substring.
+     */
+    public static function endsWith (str :String, substr :String) :Boolean
+    {
+        var startDex :int = str.length - substr.length;
+        return (startDex >= 0) && (str.indexOf(substr, startDex) > 0);
+    }
+
     /**
      * Utility function that strips whitespace from the ends of a String.
      */