Use flake8 + hacking instead of pep8, hacking.py and pyflakes

[Sergey Lukjanov]

tox -epep8 should perform all checks.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/26942

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/26942
Committed: http://github.com/stackforge/savanna/commit/964aefcaea491dda6502ba289de68fd827ef8cdb
Submitter: Jenkins
Branch: master

commit 964aefcaea491dda6502ba289de68fd827ef8cdb
Author: Sergey Lukjanov <email address hidden>
Date: Mon Apr 15 13:15:05 2013 +0400

    All tools modev to tox.

    * pep8 + copy-pasted hacking.py + pyflakes are replaced with flake8 + hacking;
    * pylint and docs envs are added to tox;
    * all tools are now links to tox.

    Change-Id: I142a1d3f9c80dab4bf145890bb066c86b7a9c376
    Fixed: bug #1169032