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

Iterator/FilterIterator.php

@@ -29,7 +29,7 @@ abstract class FilterIterator extends \FilterIterator
      */
     public function rewind()
     {
-        if (PHP_VERSION_ID > 50607 || (PHP_VERSION_ID > 50523 && PHP_VERSION_ID < 50600)) {
+        if (\PHP_VERSION_ID > 50607 || (\PHP_VERSION_ID > 50523 && \PHP_VERSION_ID < 50600)) {
             parent::rewind();
 
             return;

Iterator/RecursiveDirectoryIterator.php

@@ -119,7 +119,7 @@ public function rewind()
         }
 
         // @see https://bugs.php.net/68557
-        if (PHP_VERSION_ID < 50523 || PHP_VERSION_ID >= 50600 && PHP_VERSION_ID < 50607) {
+        if (\PHP_VERSION_ID < 50523 || \PHP_VERSION_ID >= 50600 && \PHP_VERSION_ID < 50607) {
             parent::next();
         }