iptables-restore failure message isn't useful

[Kevin Benton]

When there is an iptables failure, it's difficult to troubleshoot because the exception references a line number from a piped in set of rules that the user can't see. (e.g. http://paste.openstack.org/show/75523/)

The rules should be dumped in this case so the user and subsequent developers fixing the bug can see the rule that caused the problem.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/86810

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/86810
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=90df728558ba1f9c1d00aab1fa9d9e9937121c4b
Submitter: Jenkins
Branch: master

commit 90df728558ba1f9c1d00aab1fa9d9e9937121c4b
Author: Kevin Benton <email address hidden>
Date: Thu Apr 10 23:51:53 2014 -0700

    Log iptables rules when they fail to apply

    Log the set of rules that causes iptables-restore
    to fail in the Linux agent iptables manager.

    If a specific rule is identified as the cause, only
    that rule and a few surrounding it will be logged to
    reduce the output.

    Closes-Bug: #1306399
    Change-Id: I8e94c1faae75760e439c5abe3d9b723548398105