rgw: encode bucket info only after setting a flag

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
rgw: init member variable

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
rgw: fix policy read

policy reading used to have exact same logic for both buckets
and objects, however, we now need to read bucket attributes
through get_bucket_info().

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
rgw: refactor policy reading

reuse bucket info, no need to reread it again.

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
rgw: keep objv_tracker on bucket info

This ties it to the specific object instance info.

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
rgw: put_bucket_info() uses objv_tracker in bucket info

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
rgw: create meta handler for bucket instance

Create utility functions for reading writing bucket entry
point and bucket instance. Add a separate meta handler for
bucket instance.

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
rgw: use new instance handler for bucket operations

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
rgw: format bucket.instance meta entries nicely

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