rgw_common: Drop 's' from subresources.

Signed-off-by <caleb.miles@inktank.com>
rgw_rest_user: Remove 's' from subresources.

Signed-off-by caleb miles <caleb.miles@inktank.com>
rgw_common: Move handling of admin subresources.

Signed-off-by caleb miles <caleb.miles@inktank.com>
rgw_common: Fix admin subresource handling.

Signed-off-by caleb miles <caleb.miles@inktank.com>
rgw_bucket: fix bucket stats.

Signed-off-by caleb miles <caleb.miles@inktank.com>
Merge branch 'wip-rest-admin-3' of github.com:ceph/ceph into wip-rest-admin-3