Support bucket-in-path

[gaul]

s3cmd supports bucket-in-hostname URLs, e.g., bucket-name.example.com/blob-name. It should also support bucket-in-path URLs, e.g., example.com/bucket-name/blob-name. Many S3 clones only provide the former and s3cmd should support both styles. References gaul/s3proxy#8.

[torrancew]

👍 here - we use Ceph's S3 API with SSL support. The desire for strong SSL validation makes subdomain-style bucket access difficult to maintain at scale with our desired CA infrastructure. Hopefully my PR makes a decent starting point to get this integrated into s3cmd proper.

[gaul]

Fixed by #416. Thanks @fviard ! I used the following configuration:

host_base = localhost:8000
host_bucket = localhost:8000