radosgw-admin: user quota interface

also add needed functionality in RGWUser

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

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
rgw: some quota fixes

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
rgw: more rgw_quota fixes

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
rgw: configure user quota also through region map

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
rgw: more quota fixes

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