Need a way to add custom nw filters to nova-base filters

[Ed Bak]

A configurable mechanism is needed to add additional nw filters per instance to the nova-base filters.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/20262

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/20262
Committed: http://github.com/openstack/nova/commit/beb9292eb13f357d9ff321f1eb7e6a49e7704d14
Submitter: Jenkins
Branch: master

commit beb9292eb13f357d9ff321f1eb7e6a49e7704d14
Author: Ed Bak <email address hidden>
Date: Tue Jan 22 17:50:24 2013 +0000

    Change to support custom nw filters.

    This change is a refactoring of NWFilterFirewall to
    create a distinct function to define base nw filters.
    The new function is called get_base_filter_list. This
    provides a convenient way to subclass NWFilterFirewall
    and redefine get_base_filter_list to add your own custom
    base filters.

    Change-Id: Ida94148fcb870830ae675839ab4f900ad798d9bb
    Fixes: bug #1103086