NSXv3: nsx resources are not being clean up during unstack

[Tong Liu]

Every time after unstack, there are still lots of nsx resources left on the backend created from neutron plugin. We need to take care of this during unstack process.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/liberty
Review: https://review.openstack.org/248287

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/248287
Committed: https://git.openstack.org/cgit/openstack/vmware-nsx/commit/?id=6634852542ba5c7381d2edb6602a8eb8bf492bfb
Submitter: Jenkins
Branch: stable/liberty

commit 6634852542ba5c7381d2edb6602a8eb8bf492bfb
Author: Tong Liu <email address hidden>
Date: Fri Sep 18 18:30:59 2015 +0000

    Cleanup utility for nsxt plugin

    If there is any resource created by OpenStack left on the NSX
    backend, we can use this utility to clean it up. The cleanup steps
    are as follows:
        1. Cleanup firewall sections
        2. Cleanup NSGroups
        3. Cleanup logical router ports
        4. Cleanup logical routers
        5. Cleanup logical switch ports
        6. Cleanup logical switches

    Usage:
        $ python nsxt_cleanup.py --mgr-ip <mgr_ip> -u <user> -p <pass>
        or
        >>> import nsxt_cleanup
        >>> nsxt = nsxt_cleanup.NSXClient('mgr_ip', 'user', 'pass')
        >>> nsxt.cleanup_os_logical_ports()
        >>> nsxt.cleanup_os_logical_switches()
        >>> nsxt.cleanup_all()

    Closes-Bug: #1518481
    Change-Id: I5e5ff73d11ce791c323627dff55655fab9dbc09a
    (cherry picked from commit 4b641bc63e891aa54b40a2511df2e2cbe98342f6)