- ADTManager is responsible for computing dependencies between ADTs so
  that definitions can be grouped.
- Simplify and generalize solver handling of RawArrays.
- Remove dead-code in fair-z3 to parse non-ground models.
- OptionManager was mostly useless, moved *Type to Library
- MapGet can be implemented as (Some-value (Select m k)),
  as the solver will treat Some-value as uninterpreted if Select yields
  a None