This commit refactors code from AgentDeploy.prepare_cleaning and
AgentDeploy.tear_down_cleaning into a common place so that it
can be reused for ISCSIDeploy. It also moves the method
agent.build_agent_options to deploy_utils module.
The following CONF options have been deprecated and renamed:
[agent]agent_erase_devices_priority => [deploy]erase_devices_priority
[agent]agent_erase_devices_iterations => [deploy]erase_devices_iterations
The old CONF options will be removed in the Mitaka release.
Change-Id: I818c9f81f5469bf5029495dc9b65259718c41cd5
Implements: blueprint iscsi-deploy-in-band-cleaning
9a35ca19b4