Merge branch '4.4'

* 4.4:
  [PhpUnitBridge] fix running simple-phpunit on Windows
  fixed UPGRADE
  fixed phpdocs
  fixed phpdocs
  [ErrorCatcher] Fixed some escaping in XML errors
  [Messenger] fix broken key normalization
  [FrameworkBundle] Allow creating chained cache pools by providing several adapters
  [FrameworkBundle] Use default_locale as default value for translator.fallbacks

Author: nicolas-grekas

bin/simple-phpunit.php

@@ -130,8 +130,9 @@
     }
     $prevRoot = getenv('COMPOSER_ROOT_VERSION');
     putenv("COMPOSER_ROOT_VERSION=$PHPUNIT_VERSION.99");
+    $q = '\\' === DIRECTORY_SEPARATOR ? '"' : '';
     // --no-suggest is not in the list to keep compat with composer 1.0, which is shipped with Ubuntu 16.04LTS
-    $exit = proc_close(proc_open("$COMPOSER install --no-dev --prefer-dist --no-progress --ansi", array(), $p, getcwd()));
+    $exit = proc_close(proc_open("$q$COMPOSER install --no-dev --prefer-dist --no-progress --ansi$q", array(), $p, getcwd()));
     putenv('COMPOSER_ROOT_VERSION'.(false !== $prevRoot ? '='.$prevRoot : ''));
     if ($exit) {
         exit($exit);