Revert "[TASK] Remove compat layer for about module"

This reverts commit 873a2e56

Change-Id: Ia120b5e78c617230804aa0a50f2a7c2c1dcbf81a
Reviewed-on: http://review.typo3.org/14175
Reviewed-by: Thomas Maroschik
Tested-by: Thomas Maroschik

typo3/sysext/about/ext_autoload.php

+<?php
+$extensionPath = \TYPO3\CMS\Core\Extension\ExtensionManager::extPath('about');
+return array(
+	'tx_about_customsections' => $extensionPath . '/interfaces/interface.tx_about_customsections.php'
+);
+?>
\ No newline at end of file

typo3/sysext/about/interfaces/interface.tx_about_customsections.php

+<?php
+/*
+ * @deprecated since 6.0, the classname tx_about_customSections and this file is obsolete
+ * and will be removed by 7.0. The class was renamed and is now located at:
+ * typo3/sysext/about/Classes/CustomSectionsInterface.php
+ */
+require_once \TYPO3\CMS\Core\Extension\ExtensionManager::extPath('about') . 'Classes/CustomSectionsInterface.php';
+?>
\ No newline at end of file