Workflow status/submit API changes

This brings the submit format more in line with current discussions.  It also separates logging from the workflow service (only the genome interface layer will know what to do about that).

The key changes to status are to introduce a "failing" status, which can only apply to DAGs and parallel by operations.  A DAG or parralel by command are "failing" if one of their sub-steps has failed, but it still has "running" steps.