N°2435.1 Portal: Split portal composer.json in 2

- Autoloader for portal files in the itop-portal-base module
- Dependencies moved to root composer.json
- Add autoloader for /core and /application content

lib/symfony/twig-bundle/Resources/config/routing/errors.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+
+<routes xmlns="http://symfony.com/schema/routing"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://symfony.com/schema/routing https://symfony.com/schema/routing/routing-1.0.xsd">
+
+    <route id="_twig_error_test" path="/{code}.{_format}">
+        <default key="_controller">twig.controller.preview_error:previewErrorPageAction</default>
+        <default key="_format">html</default>
+        <requirement key="code">\d+</requirement>
+    </route>
+</routes>