https support for nova metadata requests

[Jakub Libosvar]

Current metadata agent supports only http connection to nova metadata service. Implement https support.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/81535

[Openstack Gerrit (openstack-gerrit)]

Reviewed: https://review.openstack.org/81535
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=b5917e35acb6189079f33ebb5562b8d2288dcd4f
Submitter: Jenkins
Branch: master

commit b5917e35acb6189079f33ebb5562b8d2288dcd4f
Author: Jakub Libosvar <email address hidden>
Date: Mon Mar 17 15:02:58 2014 +0100

    Add support for https requests on nova metadata

    Adds new config value for accessing nova metadata api with SSL. In case
    nova api requires client certificate other config values were added
    providing client certificate and client private key.

    DocImpact

    Closes-bug: #1293587
    Change-Id: I782a12eb77553f4369b782071b4ad19efb82e5e2