Add models for cloud orchestration

This PR is split from original PR #333  (to be discarded). It focus only on the models for orchestrations. 
The master PR #523 covers the design and progress of the support for orchestration including AWS CloudFormation and OpenStack Heat.
![orchestration](https://cloud.githubusercontent.com/assets/7047579/4719534/6144c4e0-592a-11e4-9dc1-7d882f00f947.png)

Within that world no, but when a stack's resource starts linking to vms it can start getting confusing because of templates there.  One thought in the future is to also split the vms table into vms and templates separately, and this would confuse that effort.  @gmcculloug Thoughts?