Add Option.andThen2

[Dean177]

This is like Option.map2 but andThen rather than map

  let andThen2 (a : 'a option) (b : 'b option) ~(f : 'a -> 'b -> 'c option) :
      'c option =
    match (a, b) with Some a, Some b -> f a b | _ -> None

It would need:

• Interface file entries
• Documentation
• Tests