Pylint errors

[Kurt Griffiths]

We have a long list of pylint errors reported by the tox lint2 and lint3 envs. Let's fix all the meaningful ones and add exceptions for the remainder so we can have a clean baseline report for the future.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/106272

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/106272
Committed: https://git.openstack.org/cgit/openstack/marconi/commit/?id=ddabc98a998ad95b4b983acc23a1084d984d112b
Submitter: Jenkins
Branch: master

commit ddabc98a998ad95b4b983acc23a1084d984d112b
Author: Victoria Martínez de la Cruz <email address hidden>
Date: Fri Jul 11 02:19:32 2014 -0300

    Drop pylint due to the huge amount of false positives

    Given that pylint is raising a lot of false positives
    and that we have alternative static code checkers,
    we decided to remove pylint from the tox envlist.

    This patch also fix some pylint true positives
    and cleans up the disabled pylint tests in the codebase.

    Change-Id: I6fb4b9b4c80af452796032736e39ef064b9bcd03
    Closes-Bug: #1297994