* Drop legacy calico logic

* add calico as a daemonset

By default Calico CNI does not create any network access policies
or profiles if 'policy' is enabled in CNI config. And without any
policies/profiles network access to/from PODs is blocked.

K8s related policies are created by calico-policy-controller in
such case. So we need to start it as soon as possible, before any
real workloads.

This patch also fixes kube-api port in calico-policy-controller
yaml template.

Closes #1132

For consistancy with kubernetes services we should use the same
hostname for nodes, which is 'ansible_hostname'.

Also fixing missed 'kube-node' in templates, Calico is installed
on 'k8s-cluster' roles, not only 'kube-node'.

Includes hooks for triggering calico, kubelet, and kube-apiserver restarts
if etcd certs changed.

When running legacy calicoctl we do not specify calico hostname in
calico-node container thus we should not specify it in CNI config.

Also move 'legacy_calicoctl' set_fact task to the top.

In new `calicoctl` version nodes peering with routers is broken.
We need to use predictable node names for calico-node and the
same names in calico `bgpPeer` resources and CNI.

- Move CNI configuration creation for Calico to appropriate
network_plugin role from kubernetes/node.
- Add support for MTU configuration in Calico.

The requirements for network policy feature are described here [1]. In
order to enable it, appropriate configuration must be provided to the CNI
plug in and Calico policy controller must be set up. Beside that
corresponding extensions needed to be enabled in k8s API.

Now to turn on the feature user can define `enable_network_policy`
customization variable for Ansible.

[1] http://kubernetes.io/docs/user-guide/networkpolicies/

required for usage of Calico CNI plugin version 1.4.2

* Enforce a etcd-proxy role to a k8s-cluster group members. This
provides an HA layout for all of the k8s cluster internal clients.
* Proxies to be run on each node in the group as a separate etcd
instances with a readwrite proxy mode and listen the given endpoint,
which is either the access_ip:2379 or the localhost:2379.
* A notion for the 'kube_etcd_multiaccess' is: ignore endpoints and
loadbalancers and use the etcd members IPs as a comma-separated
list. Otherwise, clients shall use the local endpoint provided by a
etcd-proxy instances on each etcd node. A Netwroking plugins always
use that access mode.
* Fix apiserver's etcd servers args to use the etcd_access_endpoint.
* Fix networking plugins flannel/calico to use the etcd_endpoint.
* Fix name env var for non masters to be set as well.
* Fix etcd_client_url was not used anywhere and other etcd_* facts
evaluation was duplicated in a few places.
* Define proxy modes only in the env file, if not a master. Del
an automatic proxy mode decisions for etcd nodes in init/unit scripts.
* Use Wants= instead of Requires= as "This is the recommended way to
hook start-up of one unit to the start-up of another unit"
* Make apiserver/calico Wants= etcd-proxy to keep it always up

Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>
Co-authored-by: Matthew Mosesohn <mmosesohn@mirantis.com>