Brick get_connector_properties doesn't allow root_helper

[Walt Boring]

Brick's initiator/connector get_connector_properties doesn't allow you to pass in root_helper
to setup the execute properly for other projects. Cinder gets away with sudo, but nova needs the
sudo nova-rootwrap as the helper

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/42366

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/42366
Committed: http://github.com/openstack/cinder/commit/2584b3038239b6f48f540c17b36e5c891e303c58
Submitter: Jenkins
Branch: master

commit 2584b3038239b6f48f540c17b36e5c891e303c58
Author: Walter A. Boring IV <email address hidden>
Date: Fri Aug 16 08:18:09 2013 -0700

    Add root_helper param to get_connector_properties

    This patch adds the ability to pass in a custom
    root_helper for executing commands. This is needed
    for other projects that need a custom root-wrapper,
    such as nova.

    fixes Bug #1213135

    Change-Id: Ie18276ae2e736bb2276d4e9c57385d2588441428