Remove some obsolete nursery stuff
- Don't reset genetic quirks when upgrading infants to children...they're already correct.
- Removes an entire set of mostly duplicate (and slightly wrong) child datatype cleanup code from the global slave update file. We should always be using the equivalent code in App.Facility.Nursery.ChildDatatypeCleanup.
- Removes the "childsFathered" and "childsKnockedUp" child properties (which are unused, and were probably the result of an overzealous search-and-replace; the correct "slavesFathered" and "slavesKnockedUp" variables have found their way back into the object over time).