Fixes

1. Various whitespace fixes and cleanup for the incubator
2. hasAnyHands isn't a function, so let's use hasAnyArms instead.
3. Improve hero slave game rules filtering. Pregnant slaves are now filtered out automatically when seePreg is unset instead of being hardcoded by ID. Slaves under the minimum slave age are automatically filtered (which means we could theoretically add under-18 hero slaves without them showing up when they shouldn't). This mechanism can be easily extended for future game rules (for instance, if someone wanted to add catgirl hero slaves that would be excluded when seeCats isn't set).