Change memcache addresses lookup

[Stanislaw Bogatkin]

Today we use complicated procedure to lookup memcache addresses on nodes. It prevents us to override them easily and to separate/change memcache role for nodes. We should change this behavior by moving memcache addresses declaration to globals task.

For example, I want to introduce new memcache balancer and install it to all nodes. I want that after configuration all needed OpenStack services look to
127.0.0.1 to my balancer and each of my balancers looks to all nodes where memcached is really running. With our current code I must change a bunch of duplicated code in fuel-library to do so and completely unable to make balancer work over plugin. With memcache addresses in globals I can do it easily.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/255254

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/255254
Committed: https://git.openstack.org/cgit/openstack/fuel-library/commit/?id=a0792cfc77edda553a96c6a39e474ebce0322245
Submitter: Jenkins
Branch: master

commit a0792cfc77edda553a96c6a39e474ebce0322245
Author: Stanislaw Bogatkin <email address hidden>
Date: Wed Dec 9 16:12:01 2015 +0300

    Add memcached_addresses variable to hiera

    Introduce new variable to have an ability for easy override memcache servers
    addresses.

    Closes-Bug: #1524275
    Change-Id: I96c8e38e6be2fa865c870908cbbaf0d95034a952