Extract image metadata from Cinder

This patch makes nova extract image metadata if it is present in the
volume dict received from Cinder API.

The volume image metadata is received from Cinder when the
volume_image_metadata Cinder extension is loaded.

This patch is part of the work done on blueprint improve-boot-from-volume
as this metadata will be used when booting instances from volumes
without the need to supply an image just for the metadata. Subsequent
patches will make Nova consider this metadata when booting instances
without and image id.

Change-Id: I9e5925ea4147a41c41f9019933a47c5ccf756747
Add get_backdoor_port to console.

This adds a get_backdoor_port function to the console
service which enables returning the eventlet_backdoor port
from rpc for the service.

Change-Id: I3cb7d199fac8c10e4b5fdc04c403b63e75a69d2d
Add get_backdoor_port to scheduler.

This adds a get_backdoor_port function to the scheduler
service which enables returning the eventlet_backdoor port
from rpc for the service.

Change-Id: Ib88e2a9e709d5240722027c94e6762b4a3bd918c
Add get_backdoor_port to cert.

This adds a get_backdoor_port function to the cert service
which enables returning the eventlet_backdoor port from rpc
for the service.

Change-Id: Iea2b1f9587ea2749c2def921d6a0d1e86f1645ee
Report failures to mount in localfs correctly.

The wrong exception type was being thrown, which meant that the virt
disk api though the disk could be resized when it couldn't. I've
added two unit tests to cover regressions as well, but this code needs
more unit testing in general. Resolves bug 1094373.

Change-Id: I9c974e138ff90e8b7a5a40f5b31dcdb25a59622d
Merge "Extract image metadata from Cinder"
Merge "Add get_backdoor_port to cert."
Merge "Add get_backdoor_port to console."
Merge "Add get_backdoor_port to scheduler."
Merge "Report failures to mount in localfs correctly."