Rename precondition as information invariant
Rename datatype as infotype
Rename alpha/omega to dress/undress
Rename Base to Contract
Rename Choice as Contract::Or
Rename Alpha/OmegaError as Dress/UndressError
Refactor Contract::Or
Moved building logic into a Builder abstraction.
Let invariant be specified through a valid? method.
Spec for unnamed contracts
Rename ADT as Datatype