Merge branch '3.4' into 4.0

* 3.4:
  [Translation] Process multiple segments within a single unit.
  Document the container.autowiring.strict_mode option
  fix custom radios/inputs for checkbox/radio type
  Another PR template tweak
  [FrameworkBundle] Add missing XML config for circular_reference_handler. Add tests.
  fix CS
  [PropertyInfo] ReflectionExtractor: give a chance to other extractors if no properties
  Clean calls to http_build_query()
  [WebProfilerBundle] limit ajax request to 100 and remove the last one
  Add support for URL-like DSNs for the PdoSessionHandler
  [HttpFoundation] Fix missing "throw" in JsonResponse
  Improve the documentation of
  Suppress warning from sapi_windows_vt100_support on stream other than STDIO
  removed extra-verbose comments
  Fixes #26136: Avoid emitting warning in hasParameterOption()
  Added a README entry to the PR template
  [HttpFoundation] Add x-zip-compressed to MimeTypeExtensionGuesser.
  [DI] Add null check for removeChild

Http/Firewall/SwitchUserListener.php

@@ -95,7 +95,7 @@ public function handle(GetResponseEvent $event)
 
         if (!$this->stateless) {
             $request->query->remove($this->usernameParameter);
-            $request->server->set('QUERY_STRING', http_build_query($request->query->all()));
+            $request->server->set('QUERY_STRING', http_build_query($request->query->all(), '', '&'));
             $response = new RedirectResponse($request->getUri(), 302);
 
             $event->setResponse($response);

Http/Logout/LogoutUrlGenerator.php

@@ -114,7 +114,7 @@ private function generateLogoutUrl($key, $referenceType)
             $url = UrlGeneratorInterface::ABSOLUTE_URL === $referenceType ? $request->getUriForPath($logoutPath) : $request->getBaseUrl().$logoutPath;
 
             if (!empty($parameters)) {
-                $url .= '?'.http_build_query($parameters);
+                $url .= '?'.http_build_query($parameters, '', '&');
             }
         } else {
             if (!$this->router) {