db updates and choices

Assigning calls happens from simple updates.  Perhaps after all updates,
we would push to the devices so that they have the most recent data and
will always be able to tell if i a call has been assigned.  The active
call list returns data, except the blob may need to be cast to a string.

Added flow choice to validate EMS XML and added extra clause for
inserting and updating cad_data in the choice component

removed "active" field from database