spacemanager: Optimize AL/RP injection

Improves latency upon file upload.

Space manager used to intercept PoolAcceptFileMessage,
both to add access latency and retention policy to the
file attributes sent to the pool (so it can choose
precious, cached, and sticky bits) and to send an
update to pnfsmanager to store access latency and
retention policy in chimera.

This patch changes the flow slightly. First of all,
storing access latency and retention policy by sending
an update to pnfsmanager is redundant. Pools in
WriteHandleImpl#registerFileAttributesInNameSpace already
store those attributes in chimera. Second, we can inject
those attributes into the file attributes send to the
pool while doing pool selection. The pool manager will
send back those file attributes to the door. The patch
modifies the doors to pass along those file attributes
to the pool - this is just a minor modification of the
existing logic, as doors already did this exact thing
for storage info.

The result is that for each write we save an additional
queuing phase in space manager, a db transaction and
two reads from the space manager database, and an
AL and RP update in chimera.

Target: trunk
Require-notes: yes
Require-book: no
Acked-by: Paul Millar <paul.millar@desy.de>
Patch: http://rb.dcache.org/r/5938/