rgw: store region in bucket info

only handle requests that come to buckets stored in correct
region.

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
rgw: add access key to zone info

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
rgw: infrastructure to send requests to different region

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
rgw: forward bucket creation to master region

plus many fixes.

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