Entities.invokeEffectorList: give task names/tags

- Some simplistic improvements to the blank transient tasks
  that appear in the UI
- Include a description for each task (saying what effector it's
  invoking, and on what)
- Include a display name for each task (currently just "compound-invoke"
  or "invoke")
Merge pull request #595 from aledsage/fix/task-names

Entities.invokeEffectorList: give task names/tags