Make shotgun to work inside of container

[Evgeniy L]

1. The problem is postgresql not on the localhost anymore
remove hardcoded datanase credentials

https://github.com/stackforge/fuel-web/blob/master/nailgun/nailgun/settings.yaml#L398

we need to take them from /etc/nailgun/settings.yaml

2. Master node is not localhost anymore

https://github.com/stackforge/fuel-web/blob/master/nailgun/nailgun/settings.yaml#L392-L393

We have to run all command over ssh instead of localhost command. Except several commands for tarball generation.

[Openstack Gerrit (openstack-gerrit)]

Fix proposed to branch: master
Review: https://review.openstack.org/90957

[Openstack Gerrit (openstack-gerrit)]

Reviewed: https://review.openstack.org/90957
Committed: https://git.openstack.org/cgit/stackforge/fuel-web/commit/?id=c6315bdf11a39d98a3fc9d62d7de365bfaf831ec
Submitter: Jenkins
Branch: master

commit c6315bdf11a39d98a3fc9d62d7de365bfaf831ec
Author: Igor Kalnitsky <email address hidden>
Date: Mon Apr 28 16:10:41 2014 +0300

    Make shotgun to work inside containers

    Previously, the config is generated with assumption that master/postgres
    node is localhost. Since now, the addresses are getting from external
    settings file (/etc/nailgun/settings.yaml).

    Closes-Bug: 1312620
    Closes-Bug: 1313839

    Change-Id: If041cae5b06fb12e1085107147f75922a066ae37