xenapi: kernel and ramdisk missing after live-migrate

[John Garbutt]

kernel and ramdisks are not moved by the live-migrate

This means:
* need to manually clean them on the source host
* need to manually add them to the destination host

This is already implemented for migrate, but we should double check we do delete them on a migrate.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/53473

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/53473
Committed: http://github.com/openstack/nova/commit/2dc976321104b8eb52eea76a5e2c621d15b06c86
Submitter: Jenkins
Branch: master

commit 2dc976321104b8eb52eea76a5e2c621d15b06c86
Author: Christopher Lefelhocz <email address hidden>
Date: Wed Oct 23 22:47:42 2013 +0000

    xenapi: kernel and ramdisk missing after live-migrate

    After a live migration is performed with xenserver, the kernel
    and ramdisk images are not moved to destination. This means:
    * need to manually add them to the destination host
    * need to manually clean them on source host

    Adding the images is fairly straightforward by calling
    create_kernel_and_ramdisk at post_live_migration_at_destination.
    Removing images requires us to cache image ids as they are
    taken from VM record which is deleted by the time the post
    operation comes along. We use the migrate_data to cache the
    image data for removal.

    The unit tests are adjusted to handle new calls for existing
    tests.

    Fixes bug 1224561

    Change-Id: I741398db9ddb6764408878a11cf4c80544bbc901