remove gunicorn and use wsgiref

[Flavio Percoco]

Lets let deployers chose whatever they prefer, gunicorn shouldn't be a dependency.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/31620

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/31620
Committed: http://github.com/stackforge/marconi/commit/61765db141f058aff2b48c1e5d06b8e44c8042b3
Submitter: Jenkins
Branch: master

commit 61765db141f058aff2b48c1e5d06b8e44c8042b3
Author: Flaper Fesp <email address hidden>
Date: Tue Jun 4 10:02:25 2013 +0200

    Replace gunicorn with wsgiref

    The patch replaces gunicorn with wsgiref since it doesn't make sense to
    have gunicorn as dependency. Lets let deployers choose whatever the
    prefer to use as container.

    The patch also removes lib/* since marconi_paste is not needed anymore,
    the wsgi app can now be accessed through:

        `marconi.transport.wsgi.app:app`

    Backward incompatible change: bind refers now to the host and a new
    config variable was introduced to specify the port it should bind to.

    Fixes bug: #1187280
    Implements blueprint: transport-wsgi

    Change-Id: I9f7767ace5c6553e75e2f4587032d7d64b9537c4