Allow Ironic URL from config file

Currently when using username/password auth from configs with
ironic client, it's not possible to specify the ironic URL in
a config file. This commit makes that possible.

Change-Id: Ib99c48c2f80abaf42b08f36af942535d7c9ac5d1
Raise MissingParameterValue instead of Invalid

There are several functions that were raising InvalidParameterValue,
when it should be a MissingParamenteValue. This way we can differentiate
both exceptions when needed.

Change-Id: Ia5ce05e30b3fb00261854857aeef46238a8b00f8
Driver merge review comments from 111425-2-3

This review contain fixes that addresses the review comments
raised in https://review.openstack.org/#/c/111425 revisions 2 & 3.
Once these changes are merged here in Ironic, they will be
proposed as updates to the patch series over in Nova.

Change-Id: Ie7bc50a9804373c9c4f8850f4e2b201c1d01effb
Raise MissingParameterValue when validating glance info

Make use of the MissigParameterValue exception when validating the
image info from glance.

Change-Id: Ic403ef47586922ef12c111aa191b0b181028d60d
Add list() to Chassis, Node, Port objects

What it says and remove the direct calls to dbapi and switch code to
use the object interfaces.

Partial-Bug: 1314732
Change-Id: I250d7c82cc4d048b60e5f360aca26f593f77b04a
Merge "Raise MissingParameterValue instead of Invalid"
Merge "Mechanism to cleanup all ImageCaches"
Remove objectify decorator from dbapi.update_* methods

This patch removes the objectify decorator from the update_chassis,
update_port and update_node dbapi's methods. The problem with the
objectify decorator is that dbapi methods doesn't get the context,
so when forming the RPC object using the decorator we can't store the
context within the object (which is what we want to do to have consistent
object interfaces).

Also there are no parts of the code that is expecting the returned RPC
object from the dbapi.update_*() methods so we can just simply get ride
of the decorator.

Partial-Bug: 1314732
Change-Id: Ib5ac15100214b351607e1c17aa663fa4c123bc7a
Merge "Add list() to Chassis, Node, Port objects"
Merge "Allow Ironic URL from config file"
Merge "Raise MissingParameterValue when validating glance info"
Merge "Driver merge review comments from 111425-2-3"
Merge "Remove objectify decorator from dbapi.update_* methods"
Take iSCSI deploy out of pxe driver

This commit aims at separating the iSCSI deploy portions
from pxe driver so that it can reused in the newly proposed
iLO virtualmedia driver.

Implements: blueprint ironic-ilo-virtualmedia-driver
Change-Id: Id0a4b0fab797c884448a27b1cd5e3a1da05786a7