Add upgrade stuff for new versions

[OpenStack Infra]

https://review.openstack.org/355525
Dear bug triager. This bug was created since a commit was marked with DOCIMPACT.

commit ecfe03f3a8d6d8ebe2c2261c34370d5df66b153c
Author: Denis Egorenko <email address hidden>
Date: Mon Aug 15 18:17:52 2016 +0300

    Add upgrade stuff for new versions

    Following items were added to perform environment update:

      1. Add task to perform upgrade with call of apt-get dist-upgrade.
         This commands force to keep old configuration files for all
         services.

      2. If MU upgrade is enabled, we trigger all services to restart.
         The exception is for Ceph, MySQL and RabbitMQ.

    Some workarounds were implemented for following issues:

      MySQL and RabbitMQ:
        MySQL and RabbitMQ restart is managed separately from other
        services and it is disabled by default. To enable it you
        should set mu_upgrade['restart_mysql'] and mu_upgrade['restart_rabbitmq']
        to true in astute.yaml.

      Pacemaker service issue:
        If corosync package was upgraded APT (or dpkg) restarts corosync
        service and this restart kills pacemaker service. So we need to
        start it again. Also we should deny APT to stop pacemaker service
        during upgrade because it leads to unload of all pacemaker resources
        (all services under it will be stopped). That's not appropriate
        behaviour during the update process. Puppet will manage pacemaker
        service itself.

      Ceph:
        Ceph should be upgraded by following next guide [1], otherwise simple
        restart of services might break the cluster or cause a data loss.

        [1] http://docs.ceph.com/docs/master/install/upgrading-ceph/#upgrade-procedures

    DocImpact

    Related-bug: #1614893

    Change-Id: I0d7231aa5900318f75f71c698f3e1c07f8e5cfbe