Bug 1030972 - Import tasks from Bugzilla

@bobsilverberg @Osmose r?
Ah, I wanted to ask about this. We could use this field to keep a record of what "base data" was used to create all the tasks in the batch. (Our original discussion about this feature described using a "TaskTemplate" table for this purpose.) I'm not sure how useful/important it is. We could use this data to allow batches to be cloned in the future...