Be more paranoid
Fix S3 bucket deletion.
support virtualbox >=4.3.0
Merge branch 'new-vbox' of git://github.com/proger/nixops

support virtualbox >=4.3.0

Fixes #151
Use <nixpkgs/nixos> instead of <nixos>
Merge branch 'master' into containers
Add convenience command for starting a development shell
Improve container creation
Support starting and stopping containers
Remove hard-coded path