Merge branch '2.7' into 2.8

* 2.7:
  Using FQ name for PHP_VERSION_ID
  [Form] Fix \IntlDateFormatter timezone parameter usage to bypass PHP bug #66323
  Harden the debugging of Twig filters and functions
  bumped Symfony version to 2.7.29
  updated VERSION for 2.7.28
  update CONTRIBUTORS for 2.7.28
  updated CHANGELOG for 2.7.28

Author: fabpot

Parser.php

@@ -344,7 +344,7 @@ public function parsePostfixExpression($node)
 
                 $node = new Node\GetAttrNode($node, $arg, $arguments, $type);
             } elseif ('[' === $token->value) {
-                if ($node instanceof Node\GetAttrNode && Node\GetAttrNode::METHOD_CALL === $node->attributes['type'] && PHP_VERSION_ID < 50400) {
+                if ($node instanceof Node\GetAttrNode && Node\GetAttrNode::METHOD_CALL === $node->attributes['type'] && \PHP_VERSION_ID < 50400) {
                     throw new SyntaxError('Array calls on a method call is only supported on PHP 5.4+', $token->cursor, $this->stream->getExpression());
                 }