* Set ETCD_INITIAL_CLUSTER_STATE from `new` to `existing`,
because parameter `new` makes sense only on cluster assembly
stage.
* If cluster exists and current node is not a part
of the cluster, add it with command `etcdctl add member name url`.
Closes kubespray/kargo/#270
fix etcd configuration for nodes
fix wrong calico checksums
using a var name etcd_bin_dir
fix etcd handlers for sysvinit
using a var name etcd_bin_dir
sysvinit script
review etcd configuration
