PIMCORE-1957 - Code improvement in function __sleep of Object_Concrete

git-svn-id: http://www.pimcore.org/svn/pimcore/private/core/trunk@3168 1f8fe7d8-47f0-464c-8d0a-336f4953ab05
build auto version ...

git-svn-id: http://www.pimcore.org/svn/pimcore/private/core/trunk@3169 1f8fe7d8-47f0-464c-8d0a-336f4953ab05