rgw: fix regionmap json decoding

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
rgw: advance ptr when sending data

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
rgw: user param in access key is not manadatory

for json decoding

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
ceph_json: reset values

Call the default constructor if entry not found. Also,
reset containers before inserting new data.

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
rgw: bilog list by bucket instance (RESTful api)

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>