add logic to handle condition where there's no NAT instance for a gateway on private network.
small nepho code changes to help with printing out just a list of deployments.
add in some pattern diagrams, and ensure patterns are working.
Merge branch 'master' of github.com:huit/nepho into feature/packaging

Conflicts:
	nepho/aws/data/patterns/common/Resources/Shared-S3-Bucket.json
	nepho/aws/data/patterns/simple-s3/development.cf
	nepho/aws/data/patterns/three-tier-ref-app/common.cf
	patterns/common/Resources/S3-Bucket.json
	patterns/common/Resources/Shared-S3-Bucket.json
	patterns/simple-s3/development.cf
	patterns/simple-s3/template.cf
	patterns/three-tier-ref-app/common.cf
	patterns/three-tier-ref-app/template.cf