Conductor de-registers on shutdown

Conductor service should de-register itself upon shutdown.
This will cause RPC requests to immediately stop routing to it
rather than there being an unnecessary period of malfunction
before the next heartbeat cycle.

A new unit test (test_stop_unregisters_conductor) is added to
validate the de-registration of the conductor. Test hostname
values are coalesced into a single variable for consistency.

Co-Authored-By: David Shrewsbury <shrewsbury.dave@gmail.com>

Change-Id: I1feea2c0165cde36f2abb95c3fa3484c73dfd81c
Better instance-not-found handling within IronicDriver

Improve the handling of failed spawns and multiple deletes within the
IronicDriver.

Change-Id: I284f4669ba14db7bb33b5a53512b6a3822ad170c
Fix help string for a glance option

The help for 'glance_api_servers' configuration option referred to
'nova'. This changes it to refer to 'ironic' instead.

Change-Id: I9aed3bc1b883b21d328ce7beebd6ed70e5d87ee6
Change set_console_mode() to use greenthreads

This method now uses a worker thread to set the console mode asynchronously
similarly to several other methods.

Followup patch to changes Ia707766855bd7ec47a5af05e119b126504ddc0b1 and
Ie03afd66d365e48c9dc3dc48f31e93a08e07e79f.

Co-Authored-By: Michael Davies <michael@the-davies.net>

Change-Id: I96d4214ba86f2b1d489b5120c379adfca28a0a7d
Partial-Bug: #1285507
Documentation for deploying DevStack /w Ironic

Adds a section to the developer quickstart doc explaining
how to deploy Ironic as part of devstack.

Change-Id: I26a6f8faa882bfaa94dd6eb26e6bef197f12b25c
Merge "Conductor de-registers on shutdown"
Merge "Fix help string for a glance option"
Merge "Documentation for deploying DevStack /w Ironic"
Merge "Better instance-not-found handling within IronicDriver"