Adaption Key-Value Store for eClass support

git-svn-id: http://www.pimcore.org/svn/pimcore/private/core/trunk@2495 1f8fe7d8-47f0-464c-8d0a-336f4953ab05
checkstyle

git-svn-id: http://www.pimcore.org/svn/pimcore/private/core/trunk@2496 1f8fe7d8-47f0-464c-8d0a-336f4953ab05
extended asset test so that it also checks that properties can be created via REST

git-svn-id: http://www.pimcore.org/svn/pimcore/private/core/trunk@2497 1f8fe7d8-47f0-464c-8d0a-336f4953ab05