Servers which isn't a jenkins slave should not be shown in jenkins nodes list

[Alexander Charykov]

At the moment we show servers which were deleted from Jenkins as Jenkins node with N/A Jenkins instance.

As this server is not Jenkins slave anymore it should not be shown as Jenkins slave and same back link from Inventory Object should be removed.

We will save info that this server was a Jenkins slave or master and it's old labels, but it would be implemented in audit feature.

[Fuel Devops McRobotson (fuel-devops-robot)]

Fix proposed to branch: master
Change author: Alexander Lomski <email address hidden>
Review: https://review.fuel-infra.org/22424

[Fuel Devops McRobotson (fuel-devops-robot)]

Change abandoned by Alexander Lomski <email address hidden> on branch: master
Review: https://review.fuel-infra.org/22424
Reason: A different approach will be used.

[Fuel Devops McRobotson (fuel-devops-robot)]

Fix proposed to branch: master
Change author: Alexander Lomski <email address hidden>
Review: https://review.fuel-infra.org/22505

[Fuel Devops McRobotson (fuel-devops-robot)]

Reviewed: https://review.fuel-infra.org/22505
Submitter: Alexander Charykov <email address hidden>
Branch: master

Commit: 44894ca234f49cbb17996e553d7ef4ab532bfaf9
Author: Alexander Lomski <email address hidden>
Date: Thu Jun 23 14:28:40 2016

Orphaned Jenkins slaves are now deleted at import.

All Jenkins slave objects which are no longer referenced by a Jenkins
CI instance will now be deleted at import. Any orphaned slaves already
present in the database will stay there until next import run.

Closes-Bug: #1595111
Change-Id: I163a6f8d7efaf97fd09e23b59c1dd58ae3d9870f