Eventlet green threads not released back to pool

[OpenStack Infra]

https://review.openstack.org/130839
commit 16a821e00d15520d2f6e940e184bd289b8782620
Author: abhishekkekane <email address hidden>
Date: Tue Oct 21 04:39:59 2014 -0700

    Eventlet green threads not released back to pool

    Presently, the wsgi server allows persist connections. Hence even after
    the response is sent to the client, it doesn't close the client socket
    connection. Because of this problem, the green thread is not released
    back to the pool.

    In order to close the client socket connection explicitly after the
    response is sent and read successfully by the client, you simply have to
    set keepalive to False when you create a wsgi server.

    DocImpact:
    Added http_keepalive option (default=True).

    SecurityImpact

    Closes-Bug: #1361360
    Change-Id: I93aaca24935a4f3096210233097dd6b8c5440176