CFY-768 add node_instances to plan which containes the bare minimum to describe the instance graph. nodes in plan now contains the original nodes and not the node instances
CFY-768 plan now includes node_instances which is a the bare minimum required for a node instance
Merge pull request #4 from cloudify-cosmo/feature/CFY-768-reduce-plan-size

Reduce plan size
Merge branch 'develop' into feature/CFY-759-repo-optimizations