Fixes #11. result-wise, forking a million task with a single edt, goes from 122mb of task and 45mb of events down to 91mb and 30mb respectively. The current design may evolve in the future. For now we assume there's a single fct_ptrs singleton as there's really only one type of task and event. In the future we may extend ocr factories definitions to include more singletons, i.e. sticky, bucket, etc... events.