Fix hosts mapping for conductor's periodic tasks

If node has a driver which does not supported by some conductors
_sync_power_states and _check_deploy_timeouts periodical tasks
will be broken for this conductors (KeyError raised in mapping
check).
New _mapped_to_this_conductor() method with fix added to
ConductorManager.

Change-Id: I4bceabab0b931e970ea7136a66ea8762ce99a52b
Merge "Fix hosts mapping for conductor's periodic tasks"