Providing kubeconfig file is now the switch for standalone mode

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.

cluster/photon-controller/templates/create-dynamic-salt-files.sh

@@ -39,6 +39,7 @@ apiVersion: v1
 kind: Config
 clusters:
 - cluster:
+    server: https://${KUBE_MASTER_IP}
     insecure-skip-tls-verify: true
   name: local
 contexts:

cluster/photon-controller/templates/salt-master.sh

@@ -29,6 +29,7 @@ grains:
   cloud: photon-controller
   master_extra_sans: $MASTER_EXTRA_SANS
   api_servers: $MASTER_NAME
+  kubelet_kubeconfig: /srv/salt-overlay/salt/kubelet/kubeconfig
   kube_user: $KUBE_USER
 EOF