VPC and SubNet should be able to be passed in as parameters

[Steve Baker]

For example https://s3.amazonaws.com/cloudformation-templates-us-east-1/VPC_WordPress_Single_Instance_With_RDS.template

The current VPC and Subnet implemenation use the resource name as the resource_id, so an existing quantum net or subnet ID cannot be passed into a template.

Since a VPC is backed by a quantum net, and Subnet is backed by a quantum subnet, then we can use the underlying quantum IDs for the resource IDs.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/23390

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/23391

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/23497

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/23391
Committed: http://github.com/openstack/heat/commit/63882b7bcbc55e411db26b4689f9cfe30d5a722b
Submitter: Jenkins
Branch: master

commit 63882b7bcbc55e411db26b4689f9cfe30d5a722b
Author: Steve Baker <email address hidden>
Date: Mon Mar 4 10:49:37 2013 +1300

    Use quantum IDs for VPC, Subnet, RouteTable resources

    Previously the resource IDs were the resource names
    so an already existing quantum entity cannot be passed into a
    template.

    Fixes: bug #1142812

    Change-Id: I9ea6561674d88dbbdd82b7c69400a70c529c4525