Fix bugs in bulk and slo and small doc change.

Added 411 responses in bulk and slo when needed.

Make X-Static-Large-Object an illegal header with slo installed- somehow
that got lost with some refactor I did.

Change-Id: I986c1656658f874172860469624118cc63bff9bc
(cherry picked from commit 92e877ae51d3bbcb21278426e07eefe703c6ad30)