Cleanup packaging to prepare for release

[Stanislaw Pitucha]

There are various issues with packaging metadata. At least the following should be fixed before the release:

- ignore autogenerated files
- allow unified py2/py3 wheel building
- cleanup declared list of validators
- add sample config files to the package

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/283394

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/283394
Committed: https://git.openstack.org/cgit/openstack/anchor/commit/?id=7a85d86f7cc160b61eb4701eaab8846f08b6ade0
Submitter: Jenkins
Branch: master

commit 7a85d86f7cc160b61eb4701eaab8846f08b6ade0
Author: Stanisław Pitucha <email address hidden>
Date: Tue Feb 23 16:56:55 2016 +1100

    Install sample configuration into etc/anchor

    Change-Id: Id10936468d7f3932e1b4b0c0def386a17310cbb0
    Partial-Bug: #1548610

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/276962
Committed: https://git.openstack.org/cgit/openstack/anchor/commit/?id=65621def14a13172919e3d5b40bd2c7a5b302bc5
Submitter: Jenkins
Branch: master

commit 65621def14a13172919e3d5b40bd2c7a5b302bc5
Author: Stanisław Pitucha <email address hidden>
Date: Sat Feb 6 11:04:21 2016 +1100

    Clean up validator lists

    Move signature validation to standards validators. Remove old validator entries
    from the setup.cfg.

    Partial-Bug: #1548610
    Change-Id: I667b0ad1a49766c2df09489ea3a11e0e77bc4333

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/282928
Committed: https://git.openstack.org/cgit/openstack/anchor/commit/?id=9456ced8115ae0eeda059b9f33db45c0b667c93b
Submitter: Jenkins
Branch: master

commit 9456ced8115ae0eeda059b9f33db45c0b667c93b
Author: Stanisław Pitucha <email address hidden>
Date: Mon Feb 22 12:52:28 2016 +1100

    Don't track autogenerated files

    Partial-Bug: #1548610
    Change-Id: I779652bd2a3e085bb6d3c091f8f4f24c0af306c1

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/282932
Committed: https://git.openstack.org/cgit/openstack/anchor/commit/?id=a1d7e9a9a50b50b44bec420108899c5cf2698274
Submitter: Jenkins
Branch: master

commit a1d7e9a9a50b50b44bec420108899c5cf2698274
Author: Stanisław Pitucha <email address hidden>
Date: Mon Feb 22 13:12:08 2016 +1100

    Anchor is source-only, so build common py2/py3 wheel

    Partial-Bug: #1548610
    Change-Id: Ic5c89f79e5d7bd0c758593ffb074f5e6d7efc71d