MongoDB deployment in HA and simple mode should be the same

[Alexander Kislitsky]

Release 5.0

Steps:
- Create environment in simple mode
- Add controller, compute, number of mongo nodes
- Deploy changes

Expected:
One mongo node should be primary-node
Other nodes should be in replset

[Max Mazur (mmaxur)]

Replica set is not supported in simple mode

[Dmitry Ilyin (idv1985)]

This patch addresses the issue of adding many mongo nodes in simple mode https://review.openstack.org/#/c/89665/
It also requires some nailgun fixes https://review.openstack.org/#/c/89895/

[Openstack Gerrit (openstack-gerrit)]

Reviewed: https://review.openstack.org/89665
Committed: https://git.openstack.org/cgit/stackforge/fuel-library/commit/?id=7effd0b11a430ddf77af55117cea97b19f4c8315
Submitter: Jenkins
Branch: master

commit 7effd0b11a430ddf77af55117cea97b19f4c8315
Author: Dmitry Ilyin <email address hidden>
Date: Wed Apr 23 22:30:50 2014 +0400

    Refactoring of mongodb host selector

    * Moving ugly puppet logic into a function.
    * Making simple mode work same as HA mode
      with primary and slave nodes

    Change-Id: Ic5a334364afcd3673d1353db3685025e9da40b97
    Closes-bug: 1308988