[rackspace] removing :host from list of request parameters. See PR #2223 for details.
Merge pull request #2235 from rackspace/host_warn

[rackspace] removing :host from list of request parameters. See PR #2223...
Merge pull request #2229 from alphagov/handling_bad_request_for_vapp_power_actions

vapp returns false if power action returns bad_request
[vcloud_director] Cater for email@org_name usernames.