Implement reset-state (os-reset_status) action

This change implements a reset-state method in the
cinderclient which exposes the extension: os-reset_status
from the Cinder API.

Fix bug 1190731

Change-Id: I8f631f0f19ca16e0fdd1e3adcf923cc684292887
Merge "Implement reset-state (os-reset_status) action"