transfermanagers: Send subject and updated file attributes to pool

In contrast to other doors, transfermanager does not inject the subject
and updated file attributes intp the pool io file message it sends to pool.
Space manager in master requires this information and thus cannot work
with transfermanagers unless the correct information is injected.

Target: trunk
Require-book: no
Require-notes: no
Acked-by: Paul Millar <paul.millar@desy.de>
Patch: http://rb.dcache.org/r/6413/