Pay attention to all punctual nodes

The proxy sends requests to all storage nodes, but it only needs a
quorum of them to respond before the proxy can, in turn, respond to
the client. Thus, it gets quorum, and then briefly waits to see if the
remainder of the storage nodes respond before giving up on them.

However, the proxy was not paying any attention to the responses from
the non-quorum storage nodes. This would lead to some odd behavior,
like a container PUT where the backends returned (201, 201, 202) would
become a 201 to the client, but the permutation (201, 202, 201) would
become 202. Further, on object PUT, if the last node responded with an
error code, that error wouldn't count towards error-limiting.

The fix is quite simple: after getting quorum, the make_requests()
method was calling a method that returns responses from the remainder
of the nodes, but it was ignoring that return value and making up
responses with dummy values instead. Now, prior to making up dummy
responses, the proxy first uses the responses it already has, and only
fills in dummy responses for nodes that really didn't respond in time.

Change-Id: I0206b6b2272b0e7dcc80fb6c51840d8dae25cee2
Merge "Pay attention to all punctual nodes"