CORE-1837 Add tgt stop, fix unmounts and service stops

The step to stop tgtd was missing for controllermgmt nodes hence
causing what was observed in CORE-1837.  This commit adds the
stop_tgt.yml file as in include for controllermgmt nodes.

During the course if this investigation, it was found that the
remounting call was missing from a number of server classes,
which has been corrected, although shifted to a pure unmount
as there appear to be image differences that make a remount
less reliable.

Additionally, the unmount and cinder volume cleanup will call
another include to cause open files to be listed out into the
log for easy troubleshooting.  This resulted in a few missing
services being identified and added.

Change-Id: I4ddc475f925875a4c8e20107d900d629c9a799e4