[TASK] Clean up phpDoc comments in typo3/sysext/

Clean up phpDoc comments for the following classes:

* typo3/sysext/cms/layout/conf.php
* typo3/sysext/cms/layout/db_layout.php
* typo3/sysext/cms/layout/db_new_content_el.php
* typo3/sysext/cms/layout/wizard_backend_layout.php

Clean up provides:

* Provide correct parameter names in phpDoc
* Provide correct data types in phpDoc
* CGLify phpDoc (remove tabs)

Change-Id: I685ede5314f7c603288a4be297a2a946e545addd
Resolves: #38057
Releases: 6.0
Reviewed-on: http://review.typo3.org/12071
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn