Merge pull request #13323 from yehudasa/wip-18079-2

librados: use cursor for nobjects listing

Reviewed-by: Sage Weil <sage@redhat.com>

diff --cc PendingReleaseNotes
Simple merge

diff --cc src/include/rados/librados.hpp
Simple merge

diff --cc src/librados/librados.cc
Simple merge

diff --cc src/osdc/Objecter.cc
Simple merge

diff --cc src/osdc/Objecter.h
Simple merge