Log debug option for deadlocks detector

[Andriy Popovych]

Currently when deadlock detected Nailgun shows huge debug log in output http://paste.openstack.org/show/476240/. Sometimes during development process it's annoying. We should have some option in settings to disable such behavior.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/235281

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/235281
Committed: https://git.openstack.org/cgit/openstack/fuel-web/commit/?id=22886eca8fbb2b27d6aa55acf493ebacbdf90bd2
Submitter: Jenkins
Branch: master

commit 22886eca8fbb2b27d6aa55acf493ebacbdf90bd2
Author: Alexander Kislitsky <email address hidden>
Date: Thu Oct 15 14:58:35 2015 +0300

    Setting for deadlocks detection logging added

    We should enable deadlocks detection logging only in case
    of finding and fixing deadlocks activity. In other cases
    detecging generates a lot of messages and makes log
    unreadable.

    Change-Id: Id47c2ebf5e5ff21d50d34d946a4292928353ecb9
    Closes-Bug: #1506040