Recursive project delete

By design, delete operations on any resource fail when the resource has children. In order to delete a whole project containing instances, disks, VPCs, etc., one currently has to build the tree of resource and delete everything from the leaves up. The problem is: that is often something we want to do! Currently we have some scripts that do this client-side. That may be where we land (maybe, for example, incorporating this logic into the CLI) but I wanted to track the possibility of doing this within the API. It would be a pretty complex and slow operation involved stopping potentially many instances and deleting many resources. It would probably make sense to wait for #392.

Start by reviewing the context in issue #392 and the existing client-side scripts that delete project resources from the leaves up. Determine whether the desired outcome belongs in the API or CLI, and define completion around safely stopping and recursively deleting all project resources.