add deployment.targetPort option
Merge pull request #191 from iElectric/targetPort

add deployment.targetPort option
Per Eelco's suggestion, use first configured SSH port as default for deployment.targetPort.
Support Amazon EBS SSD disks (http://aws.amazon.com/blogs/aws/new-ssd-backed-elastic-block-storage/).
add placement group
Merge pull request #199 from dguibert/dg/placement-group

add placement group
Add functionality to ensure the control host-only interface (vboxnet0) with a configured DHCP server exists before proceeding to deploy a virtualbox. Create the interface and the DHCP servers as needed. Added unittests for this functionality
Merge branch 'master' of github.com:nixos/nixops into hostonlyif