This adds two config options that we need in order to successfully build
our Rackspace images.
First, a boolean `rackconnect_wait` option which waits for the
RackConnect metadata to appear.
Second, an `ssh_interface` option, for rackconnect users who have more
prohibitive firewalls on the 'public' interface and want to ensure all
traffic to the server goes over the 'private' one.
Finishes #952.
Rackspace defaults to a public IPv4 and IPv6 address. These are returned in
random order, with the sprintf further on generating an incorrect connection
string if on IPv6. Force IPv4 until support for correct connection strings and
a configuration flag for logging in over IPv6 is added.
This change adds base support for an openstack builder.
Thank you to Rackspace for providing cloud assets to complete this work
and @sam-falvo for working with us on the perigee/gophercloud changes.