This PR fixes a regression where the remote bucket policies
were not updated due to policy.Resource not having exported
fields, gob fails with unexported fields while marshalling.
- remove old bucket policy handling
- add new policy handling
- add new policy handling unit tests
This patch brings support to bucket policy to have more control not
limiting to anonymous. Bucket owner controls to allow/deny any rest
API.
For example server side encryption can be controlled by allowing
PUT/GET objects with encryptions including bucket owner.