Fake clientset no longer needs to be prepopulated with records: keeping
them in leads to the name conflict on creates. Also, since fake
clientset now respects namespaces, we need to correctly populate them.
This commit adds a new volume manager in kubelet that synchronizes
volume mount/unmount (and attach/detach, if attach/detach controller
is not enabled).
This eliminates the race conditions between the pod creation loop
and the orphaned volumes loops. It also removes the unmount/detach
from the `syncPod()` path so volume clean up never blocks the
`syncPod` loop.
