Replaces use of --api-servers with --kubeconfig in Kubelet args across
the turnup scripts. In many cases this involves generating a kubeconfig
file for the Kubelet and placing it in the correct location on the node.
This adds a simple CNI configuration which is added to the node during test setup.
This also modifies the default flags in services/kubelet.go to specify the "cni-bin-dir"
and the "cni-conf-dir" and removes the "network-plugin-dir" flag. This leaves the default
network plugin to kubenet.
