[vcloud_director] ensure that MetadataEntry is a list
[vcloud_director] Show guest customization "admin password auto"

Guest customization setting "admin password auto" was retrieved but not
shown.
[vcloud_director] Handle Guest admin password

Admin passwords can be retrieved and modified using the VMWare console,
so it's useful to allow the same operations here.

Moreover, when an admin password is enabled and "admin password auto" is
false, it's impossible to modify Guest settings.
i.e., "The administrator password cannot be empty when it is enabled and
automatic password generation is not selected."

This patch also fixes `put_guest_customization_section_vapp` where an
AdminPassword element was never created.
Add ready? method to aws VPC and Subnet models
changed __consoles to consoles and renamed consoles method to get_consoles
fixed tests
[aws|rds] Support Iops parameter

Allow an RDS instance to be provisioned with an amount of
provisioned IOPS.
Allow custom Mock.not_implemented message
[xenserver] Updated models to have all attributes from version 6.2.0
Merge pull request #2471 from alphagov/allow_mock_not_implemented_message

Allow custom Mock.not_implemented message
[rackspace|queues] adding the queues getting started guide
openstack modifications

* add model and collection for security group rules
* add mock data for networks
* returns address in create_server mock
* proper security group rule mocks
* proper security group mocks
[rackspace] apply documentation edits
Allow custom Mock.not_implemented message
Add pending -> available transitions for AWS VPC and Subnets
Use OpenSSL::Digest instead of deprecated OpenSSL::Digest::Digest
Add exponential backoff to backoff_if_unfound.
Merge pull request #2473 from amatsuda/digest_digest

Use OpenSSL::Digest instead of deprecated OpenSSL::Digest::Digest
Merge pull request #2466 from sugarb/vpc_and_subnet_ready

Add ready? method to aws VPC and Subnet models
Merge pull request #2472 from zertico/updating_xen_server_attributes

[xenserver] Updated models to have all attributes from version 6.2.0