More refactor work.

- Remove all noOverflow and flatten options from Options
- setFlatten() could not be removed because it's called from many
  places, even though nothing actually happens in the original code
- Fixed typo: ParertoPoint -> ParetoPoint
    - Note that this requires changes to Alloy
      (commit ab3ffd66886fb53ccbdd5197c0c81b7e0af840a2)