Add Clever CMS, AJAX Layered Nav, MetaRobots

* Add Netresearch Product Visibility extension
* Remove Schumacher FM CMS restriction extension (replaced by Clever CMS)
* Add JR Clever CMS extension
* Add Catalin SEO Ajax Layered Nav extension
* Upgraded Fontis Blog to v1.1.1
* Move the Yoast MetaRobots extension into core
* Add recursive filters to custom vars for CMS and email content
* Fix for exception error reports in errors/processors.php
* Move cron.sh, mage and install.php into the shell directory
* Remove htaccess files