Template: sftpcloudfs/auth-url
Type: string
Default: https://auth.api.rackspacecloud.com/v1.0
_Description: Content of the auth-url directive:
 In order to authenticate it's users, SFTPCloudFS needs to connect to an
 authentication server (eg RackSpace Cloud Files, OpenStack). Enter the
 URL of that server.
 .
 For Rackspace in US, choose https://auth.api.rackspacecloud.com/v1.0
 .
 For Rackspace in UK, choose https://lon.auth.api.rackspacecloud.com/v1.0
 .
 If you use Swift, something like this will do: https://example.com/v1.0
 (or use the IP address directly).
