1130119 - do not add full task info to spawned_tasks

Previously, the entire task object was being added to spawned task results in
certain cases when a consumer agent notification was occuring.  Instead, it
should just be the task_id.

Additionally, add note to 2.4.2 release notes.
Merge pull request #1129 from beav/task_id

1130119 - do not add full task info to spawned_tasks