Provide access to outputs from OS::Heat::ResourceGroup

To align with the related OS::Heat::AutoScalingGroup change:
Ib9e830e0c54602ac456d64179e1df30f0778906d

This adds an 'attributes' attribute to the OS::Heat::ResourceGroup resource
so that the following:
  {'get_attr': ['my_asg', 'attributes', 'networks', '<network_name>', 0]}
returns a mapping from resource names to the corresponding IP addresses.

There is no need for an outputs_list attribute since the following already
returns a list:
  {'get_attr': ['my_rg', 'networks', '<network_name>', 0]}

To align ResourceGroup with OS::Heat::AutoScalingGroup, there will
be a proposed change to OS::Heat::AutoScalingGroup to rename the
following attributes:
- outputs -> attributes
- outputs_list -> attributes_list

Change-Id: Id51f23533ae75ca5d883a4f67e75ac9513a67264
Implement OS::Heat::SoftwareDeployments

This is a resource which subclasses ResourceGroup to deploy a group
of OS::Heat::SoftwareDeployment resources

The main difference in properties between this resource and
OS::Heat::SoftwareDeployment is that it has a 'servers' property
instead of 'server'. The servers property expects a map of
resource-name/nova-uuid pairs. The resource name is used as the
deployment resource name inside the group, and the nova-uuid is used
as the server to deploy to.

The attributes deploy_stdouts, deploy_stderrs, deploy_status_codes
each return a map where the key is the server name and the value
is the respective attribute from the deployment resource.

Change-Id: Ide1e8fb57d45062e5d459b484135a5cad6d2c7dc
Partial-Blueprint: deployment-multiple-servers
Implement OS::Heat::StructuredDeployments

This is a resource which subclasses SoftwareDeployments to deploy a group
of OS::Heat::StructuredDeployment resources

Change-Id: I5f9603c68bb7cd81ef60a6b2ba965e5b8e93887a
Implements-Blueprint: deployment-multiple-servers
Merge "Provide access to outputs from OS::Heat::ResourceGroup"
Merge "Implement OS::Heat::SoftwareDeployments"
Merge "Implement OS::Heat::StructuredDeployments"