Fix can not be used devicemapper driver

Cloud resolvers are mandatory for hosts on GCE and OpenStack
clouds. The 8.8.8.8 alternative resolver was dropped because
there is already a default nameserver. The new var name
reflects the purpose better.

Also restart apiserver when modifying dns settings.

Bump kube-dns to 1.14.8

DNS entries generated from 'etcd_cert_alt_names' variable in etcd's
openssl.conf are not terminated by a newline.

This fixes issue #2207.

Support ipvs mode for kube-proxy

import_tasks will consume far less memory, so it should be
used whenever it is compatible.

Raise drain timeout to 5m

* iptables: flush nat table as well as filter table upon reset

* Indentation fix

Renamed variable from disable_volume_zone_conflict to volume_cross_zone_attachment and removed cloud provider condition; fix identation

Fix 'no such host' problem reported by commands *kubectl logs* and *kubectl exec*
when cloud_provider is OpenStack

Closes: #2147

kube-proxy is complaining of missing modules at startup. There is a plan
to also support an LVS implementation of kube-proxy in additon to
userspace and iptables

* Add support for cert alt names for etcd

* Update gen_certs_vault.yml

Simplify the number of variables necessary to "just" enable OpenStack
cloud provider. Also add the new options available in K8s 1.9.

Auto configure API access endpoint with a custom bind IP, if provided.
Fix HA docs' http URLs are https in fact, clarify the insecure vs secure
API access modes as well.

Closes: #issues/2051

Signed-off-by: Bogdan Dobrelya <bogdando@mail.ru>