Shutdown virtualbox nodes should restart on lein pallet up

[dgtized]

This is related to #227, so the description there may help. If a node is shutdown in virtualbox, but pallet believes it should control it, it doesn't restart it. When you run lein pallet up, it leaves it off, and but tries to connect using whatever the updated admin user is. It seems reasonable to do this, but it should start the node before doing that, instead of timing out on sshing into a node that is off.