eslint revert

1. Remove albinism stuff from getHeroSlave and just let deepAssign handle the albinism override.
2. Make deepAssign handle null values better, so it doesn't puke over the albinism override.
3. Refactor hero slave cost calculation to a separate function instead of repeating the same inscrutable logic multiple places.

Don't use a separate ID scheme for infants in the nursery.  Generate all IDs exactly the same way and never change them during a slave's life.

2. Replace <<EventNameLink>> with either App.UI.slaveDescriptionDialog or contextualIntro as relevant to each call site.
3. Get rid of <<EventNameDelink>> (and <<SetPregType>> which is obsolete and unused).
4. Document the changes for event writers.

Use a dialog to display the event slave description instead of wedging it into the middle of the event text.