Updated owner checks to function _test_owner().

In order to be compatible with other CM systems, the owner parameter is
accepted, but can have a long-term side-effect of having inconsistencies
across salt states.  Rather than let this fester, issue a sensible
warning and give the user direction on how to fix the problem.
Merge pull request #3682 from rca/develop

Updated owner checks to function _test_owner().