No log for ipsec pluto process

[LIU Yulong]

Add log for ipsec pluto process

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/214701

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/214701
Committed: https://git.openstack.org/cgit/openstack/neutron-vpnaas/commit/?id=b003d9a4242904b042b251f8597fe3b00b5175ab
Submitter: Jenkins
Branch: master

commit b003d9a4242904b042b251f8597fe3b00b5175ab
Author: changzhi <email address hidden>
Date: Thu Aug 20 00:26:35 2015 +0800

    Allow enabling detailed logging for OpenSwan

    Add log for IPSec pluto process. This log will be useful
    to developers for debug IPSec site connection and IPSec
    connectivity.

    This applies to OpenSwan and Libraswan, and that StrongSwan
    has logging that logs to syslog.

    DocImpact
    Closes-Bug: #1484410
    Change-Id: Id150416a179ae4ddeed5bd13d6c50793e6183f55