Refactoring: Added support for method chaining

git-svn-id: http://www.pimcore.org/svn/pimcore/private/core/trunk@2377 1f8fe7d8-47f0-464c-8d0a-336f4953ab05
added class update script

git-svn-id: http://www.pimcore.org/svn/pimcore/private/core/trunk@2378 1f8fe7d8-47f0-464c-8d0a-336f4953ab05
Bugfix: Document_Service::render() not overwriting passed $params on sucessive calls
http://www.pimcore.org/issues/browse/PIMCORE-1861

git-svn-id: http://www.pimcore.org/svn/pimcore/private/core/trunk@2379 1f8fe7d8-47f0-464c-8d0a-336f4953ab05