asset refactoring: using streams/file-handles instead of blobs

git-svn-id: http://www.pimcore.org/svn/pimcore/private/core/trunk@3815 1f8fe7d8-47f0-464c-8d0a-336f4953ab05
asset stream refactoring: fixed problem with copy/paste & moving assets

git-svn-id: http://www.pimcore.org/svn/pimcore/private/core/trunk@3816 1f8fe7d8-47f0-464c-8d0a-336f4953ab05
build auto version (2938) ...

git-svn-id: http://www.pimcore.org/svn/pimcore/private/core/trunk@3817 1f8fe7d8-47f0-464c-8d0a-336f4953ab05