fuelmenu dhcp check should run once per interface

[Matthew Mosesohn]

We should run dhcp check early on in the background and set dhcp probe results globally in fuelmenu. There is an event scheduler already used by urwid, documented here: http://urwid.org/manual/mainloop.html#event-loops
Getting this DHCP information early and not obtrusively will allow fuelmenu to operate much faster and greatly improve user experience.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/119014

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/119014
Committed: https://git.openstack.org/cgit/stackforge/fuel-web/commit/?id=fc24c30cac34b9edad62f4f368d8b98f2ccb4530
Submitter: Jenkins
Branch: master

commit fc24c30cac34b9edad62f4f368d8b98f2ccb4530
Author: Matthew Mosesohn <email address hidden>
Date: Thu Sep 4 13:27:52 2014 +0400

    Add check for dhcp range overlap in fuelmenu

    Change-Id: Ie666ee7e83b99f0ba544e8e90f82000b0aa12a96
    Closes-Bug: #1365395

[Matthew Mosesohn (raytrac3r)]

This is not a duplicate and I marked the commit fc24c30cac34b9edad62f4f368d8b98f2ccb4530 as related to this bug in error. Please disregard and this is actually still a confirmed bug unresolved.

[Matthew Mosesohn (raytrac3r)]

Nikolay said he would help work on a threading function to evaluate dhcpcheck on all interfaces simultaneously in the background.

[Nikolay Markov (nmarkov)]

I'm not sure we really need this as well as fuelmenu itself. Moving this back to team for now.

[Vladimir Sharshov (vsharshov)]

Moving to 8.0 because it is feature.

[Alexander Kislitsky (akislitsky)]

We passed SCF in 8.0. Moving the bug to 9.0.