Add go examples

Code and site changes to support the Go programming language and, specifically, Gophercloud v1.
`ExtractHeaders` no longer exists!

On a Get call, this is `ExtractMetadata()` now... but others flat-out don't exist. This is probably a shortcoming in Gophercloud. I *think* all of these calls return metadata in their headers, so [ExtractMetadata](https://github.com/rackspace/gophercloud/blob/c8c73bcef034d3c6e665b01e05625269c0325197/openstack/objectstorage/v1/containers/results.go#L110) should probably be defined on `commonResult`, not just `GetResult`. @jamiehannaford, @jrperritt, what do you think? I only touched object storage a little.