support guru meditation reports

[Li Ma]

https://wiki.openstack.org/wiki/GuruMeditationReport

https://review.openstack.org/#/c/303642

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/257838
Committed: https://git.openstack.org/cgit/openstack/dragonflow/commit/?id=7eb5abdf4e3455ff094ba270e1d141a6595a2e9c
Submitter: Jenkins
Branch: master

commit 7eb5abdf4e3455ff094ba270e1d141a6595a2e9c
Author: Li Ma <email address hidden>
Date: Sat Dec 12 20:31:39 2015 +0800

    Remove explicit eventlet.monkey_patch()

    Change-Id: Idacf87355d6efabcd0d2714f05b4285ac39ad08b
    Closes-Bug: #1522784
    Related-Bug: #1568220

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/326813
Committed: https://git.openstack.org/cgit/openstack/dragonflow/commit/?id=b457e8f0ab8e620996b5bbb2ac412aaf4804061e
Submitter: Jenkins
Branch: master

commit b457e8f0ab8e620996b5bbb2ac412aaf4804061e
Author: Li Ma <email address hidden>
Date: Wed Jun 8 11:55:10 2016 +0800

    Implement Guru meditation reports

    Guru can log runtime configuration of a given process, along with
    thread status and greenthread status. It greatly help check the
    process runtime status.

    The usage is simple:
    kill -USR2 {process-id}

    In dragonflow, you can show the reports of df-controller,
    df-publisher, df-l3-agent, and the coming df-metadata-service.

    The description is as follows:
    https://wiki.openstack.org/wiki/GuruMeditationReport

    Closes-Bug: #1568220
    Change-Id: I24048e1018ba3710b7a7476ca1dd83a5ae38894a