fixed some deprecation messages

Author: fabpot

Generator/UrlGenerator.php

@@ -127,7 +127,7 @@ public function generate($name, $parameters = array(), $referenceType = self::AB
     protected function doGenerate($variables, $defaults, $requirements, $tokens, $parameters, $name, $referenceType, $hostTokens, array $requiredSchemes = array())
     {
         if (is_bool($referenceType) || is_string($referenceType)) {
-            @trigger_error('The hardcoded value you are using for the $referenceType argument of the '.__CLASS__.'::generate method is deprecated since version 2.8 and will not be supported anymore in 3.0. Use the constants defined in the UrlGeneratorInterface instead.', E_USER_DEPRECATED);
+            @trigger_error('The hardcoded value you are using for the $referenceType argument of the '.__CLASS__.'::generate method is deprecated since Symfony 2.8 and will not be supported anymore in 3.0. Use the constants defined in the UrlGeneratorInterface instead.', E_USER_DEPRECATED);
 
             if (true === $referenceType) {
                 $referenceType = self::ABSOLUTE_URL;