Provide support in decision structures for automated / decision support / ad hoc modes.

The current decision structures support only a fully automated mode of processing, whereby the criteria for advancing down any branch within a group is fully defined in the definition, and assumed to be followed at runtime.

However, 3 levels of processing are needed: fully automated (i.e. what is already there), 'decision support', where the defined conditions are understood as recommendations that can be overridden by the user at execution time, and 'ad hoc;', where multiple choices are defined whose criteria / justification are only provided at execution time by the performer.