Merge branch '4.1'

* 4.1:
  Use the real image URL for the filesystem tests
  [Finder] Update PHPdoc append()
  [DI] Fix phpdoc
  Fix code examples in PHPDoc
  [HttpKernel] Fix inheritdocs
  bumped Symfony version to 3.4.16
  updated VERSION for 3.4.15
  updated CHANGELOG for 3.4.15

Author: sroze

EntryPoint/AuthenticationEntryPointInterface.php

@@ -31,10 +31,14 @@ interface AuthenticationEntryPointInterface
      * response that "helps" the user start into the authentication process.
      *
      * Examples:
-     *  A) For a form login, you might redirect to the login page
-     *      return new RedirectResponse('/login');
-     *  B) For an API token authentication system, you return a 401 response
-     *      return new Response('Auth header required', 401);
+     *
+     * - For a form login, you might redirect to the login page
+     *
+     *     return new RedirectResponse('/login');
+     *
+     * - For an API token authentication system, you return a 401 response
+     *
+     *     return new Response('Auth header required', 401);
      *
      * @param Request                 $request       The request that resulted in an AuthenticationException
      * @param AuthenticationException $authException The exception that started the authentication process