* provider/openstack: Expose LogRoundTripper fields externally
* state/remote/swift: Add support for debugging Openstack calls using
OS_DEBUG env variable.
* provider/openstack: Update LogRoundTripper to log headers aswell as body.
* Add `RedactHeaders` function in order to redact sensitive http Headers.
Refactor `logRequest` and `logResponse` to use `RedactHeaders` func.
Rework devcamcar's OpenStack Swift remote [pull
request](https://github.com/hashicorp/terraform/pull/942) to work with
Terraform's new `state/remote` and Gophercloud's current implementation.
`Get()` changed up a bit from devcamcar's version (using different
Gopercloud functionality resulted in less fussing around to figure out
the error case).
Otherwise this is a transliteration/remix of his ideas.
James Bardin