Public & Internal endpoints support

This Pull request aims to support 2 endpoints:
* one in the north, exposed to public network
* one in the south, exposed to internal network

This is part of High Availability refacto, started by @Spredzy a few months ago.

Details:
* keepalived_localhost_ip params was not used, I've deleted it.
* (option) Create an internal VIP (new VRRP instance in Keepalived)
* Rename old parameters to be used for the public VIP
* deprecate old parameters correctly and set them as public endpoint by
  default.
* (option) create HAproxy internal binding for OpenStack services
* warning if Galera Cluster is exposed on public network
* warning if Glance Registry is exposed on public network
* Fails the catalog if OpenStack or Galera IP are not in the Keepalived
VIP list. It avoids configuration mistakes.

Bug #237