rgw: get/set region map

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
rgw: enable regionmap updates

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
librados: add two more ObjectOperation::exec()

 - one that also gets out bufferlist and ret value pointer
 - one that gets a callback context

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
cls_version: create a new objclass

New objclass to track and modify objects versions.

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
cls_version: add unit tests

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
rgw: start tying metadata objs to version objclass

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
rgw: rgw_get_system_obj() can return obj_version

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
rgw: metadata set/get infrastructure

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
rgw: metadata manager, api to list keys

Also, implement key listing for user metadata.

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
rgw: put metadata, other cleanups

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
rgw: add top level metadata handler

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
rgw: user metadata updates also key version

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
rgw: metadata list user, only show uids

don't show unrelated object names

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