This change set adds support for cold migration and resize
to a different host.
Add methods to the local disk driver to retrieve and validate if
the drivers are compatible between the source and destination host.
These methods will only be called if the driver supports shared
storage. Currently only the SSP driver supports shared storage.
Add task flow implemention for migrate_disk_and_power_off.
There is a peculiar case when resizing a VM on the same host.
PowerVM doesn't allow two VMs to be defined with the same UUID,
therefore there is only one VM present on the host and care must
be taken during a resize revert not to delete the one and only VM
we have. To more easily detect that case and to easily see when
a VM is being resized or migrated, we rename the source VM during
the resize/migration processes. The renamed VM will either be
deleted or renamed back when the resize/migration operation is
confirmed or reverted.
Change-Id: Ie3afe7de9b6daca2396dbc9e2d1c1537cb85e8d9
1b5c427a73