Fix EZP-20687: added fiximagesoutsidevardir.php update script

This update script searches for image files in ezimagefile that
aren't located inside the currently configured var directory,
and moves them back in.
eZFSFileHandler::move() will now use eZFile and not eZFileHandler

This is already what eZDFS does. It adds automatic folder structure creation.
Required by the update script for EZP-20697.