Make dnsmasq daemon set optional

Change additional dnsmasq opts:
- Adjust caching size and TTL
- Disable resolve conf to not create loops
- Change dnsPolicy to default (similarly to kubedns's dnsmasq). The
  ClusterFirst should not be used to not create loops
- Disable negative NXDOMAIN replies to be cached
- Make its very installation as optional step (enabled by default).
  If you don't want more than 3 DNS servers, including 1 for K8s, disable
  it.
- Add docs and a drawing to clarify DNS setup.
- Fix stdout logs for dnsmasq/kubedns app configs
- Add missed notifies to resolvconf -u handler
- Fix idempotency of resolvconf head file changes

Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>

inventory/group_vars/all.yml

@@ -103,6 +103,8 @@ kube_apiserver_insecure_port: 8080 # (http)
 # You still must manually configure all your containers to use this DNS server,
 # Kubernetes won't do this for you (yet).
 
+# Do not install additional dnsmasq
+skip_dnsmasq: false
 # Upstream dns servers used by dnsmasq
 upstream_dns_servers:
   - 8.8.8.8