(maint) Do not fall back to the user-specified VM name when doing vcloud cleanup

The vcloud provisioning will never create a VM with the user-specified
name, so falling back to it was pointless, and could cause the harness
to delete VMs not associated with the current test run, or worse,
templates.

As a special bonus, if any hosts don't have vmhostname set, we will
warn that they were likely not provisioned correctly in the first
place.
(20880) Use the correct config hash in the vm setup library

There is (unfortunately) a difference between the puppet acceptance
config object and the configuration hash. The config hash is accessed
via the `'CONFIG'` entry in the object. This simply changes the
`@config` member of the vm controller to use the correct hash.
(maint) Rescue any cleanup exception

Previously, a failure in the cleanup step would cause any exception
from the earlier step(s) to be discarded. This manually handles
cleanup exceptions so the original failure is not masked.
(20880) Complete the conversion of vcloud spinup to a library

An old variable name from the monolithic reverter was left in the
vcloud code. This changes it to its proper modern name.