user password is now saved via the new php crypto API (password_hash() functions), WebDAV uses now Basic Auth (Digest is discontinued - as not supported by bcrypt) + updated SabreDAV to the latest version

git-svn-id: http://www.pimcore.org/svn/pimcore/private/core/trunk@4595 1f8fe7d8-47f0-464c-8d0a-336f4953ab05