Assign to Dossier: use Yearfolderstorer instead of manually moving the forwarding to the yearfolder.
Admin_unit intern `remote_requests` uses now unrestricted traversing.

It's not be secured that all parts from the traversing path,
are available for the user. But because the remote request is only used from other
intern functions, it makes sense to use `unrestrictedTraverse`.
Merge pull request #625 from 4teamwork/pg_assign_to_dossier_fix

Assign to dossier fix