Update Twig from 1.35.0 to 1.42.4 (PHP 5.5 is now required!)

This fixes some errors on PHP 7.4 and contains even more fixes
Also bumped PHP version to 5.5 as Twig requires it.

system/libs/Twig/Twig/ParserInterface.php

@@ -0,0 +1,33 @@
+<?php
+
+/*
+ * This file is part of Twig.
+ *
+ * (c) Fabien Potencier
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+use Twig\Error\SyntaxError;
+use Twig\Node\ModuleNode;
+use Twig\TokenStream;
+
+/**
+ * Interface implemented by parser classes.
+ *
+ * @author Fabien Potencier <fabien@symfony.com>
+ *
+ * @deprecated since 1.12 (to be removed in 3.0)
+ */
+interface Twig_ParserInterface
+{
+    /**
+     * Converts a token stream to a node tree.
+     *
+     * @return ModuleNode
+     *
+     * @throws SyntaxError When the token stream is syntactically or semantically wrong
+     */
+    public function parse(TokenStream $stream);
+}