Ability to use role "status" in criteria in workflows

As a workflow admin I want to be able to make path decisions based upon whether a role is populated or empty.

Notes

1. Need to be able to use the status of a named role in

   1. Criteria

      1. Start event

      2. Intermediate event

      3. Exclusive gateway

      4. Inclusive gateway

2. Need to be able to ask if a specific role is:

   1. Empty

   2. Populated