Merge pull request #11269 from yehudasa/wip-multipart-uploads-cp

rgw: multipart upload copy

Reviewed-by: Casey Bodley <cbodley@redhat.com>

diff --cc doc/radosgw/s3.rst
Simple merge

diff --cc src/rgw/rgw_op.cc
Simple merge

diff --cc src/rgw/rgw_op.h
Simple merge

diff --cc src/rgw/rgw_rest_s3.cc
Simple merge