Merge branch '3.4' into 4.0

* 3.4:
  update test for Twig performance optimizations
  [WebProfilerBundle] Increase retry delays between toolbarAction ajax calls
  support sapi_windows_vt100_support for php 7.2+
  bumped Symfony version to 3.4.5
  updated VERSION for 3.4.4
  updated CHANGELOG for 3.4.4
  bumped Symfony version to 2.8.35
  updated VERSION for 2.8.34
  updated CHANGELOG for 2.8.34
  bumped Symfony version to 2.7.42
  updated VERSION for 2.7.41
  update CONTRIBUTORS for 2.7.41
  updated CHANGELOG for 2.7.41
  [HttpFoundation] Added "null" type on Request::create docblock
  Don't stop PSR-4 service discovery if a parent class is missing.
  Allow trans filter to be safe

Author: nicolas-grekas

Output/StreamOutput.php

@@ -92,7 +92,8 @@ protected function hasColorSupport()
     {
         if (DIRECTORY_SEPARATOR === '\\') {
             return
-                '10.0.10586' === PHP_WINDOWS_VERSION_MAJOR.'.'.PHP_WINDOWS_VERSION_MINOR.'.'.PHP_WINDOWS_VERSION_BUILD
+                function_exists('sapi_windows_vt100_support') && sapi_windows_vt100_support($this->stream)
+                || '10.0.10586' === PHP_WINDOWS_VERSION_MAJOR.'.'.PHP_WINDOWS_VERSION_MINOR.'.'.PHP_WINDOWS_VERSION_BUILD
                 || false !== getenv('ANSICON')
                 || 'ON' === getenv('ConEmuANSI')
                 || 'xterm' === getenv('TERM');