EZP-23437: fixed LegacyDFSClusterTest (load)
EZP-23437: added specs/doc for DFS
EZP-23437: fixed path detection in DFS listener
EZP-23437: fixed usage of deprecated method
EZP-23437: added UrlDecorator to legacy dfs

Will be used to replace to unset prefix. The legacy url decorator
will be perfectly adapted.
EZP-23437: Changed SPI mtime to DateTime

Was supposed to be this way :)
EZP-23437: fixed usage of deprecated method