Improves upgradability of calicoctl by leveraging docker tags.

This should make things a little more composable,
by making these roles meta roles that perform no
actions by default we allow each role to own its own
resources.

using a shared folder can cause race conditions for the download
role as it tries to download files on all the nodes to the same
shared path.  This adds a flag to run the tasks in the download
role on just one node.

files.  get_url doesn't honor owner and mode is spotty.

reorder master handlers

typo for sysvinit

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