PIMCORE-2244 - Cant delete folder with 50000 objects (do not move element to recycle bin if they have more than 100 children + show warning the the UI)

git-svn-id: http://www.pimcore.org/svn/pimcore/private/core/trunk@4607 1f8fe7d8-47f0-464c-8d0a-336f4953ab05