Make2.LiftLifts functions into the monad.
A function that operates on values can be mapped to a function that operates on computations. We provide several liftes for common arities.
val nullary : 'a -> ('a, 'e) M.tnullary x lifts x (a synonym to return)
val ternary : 
  ('a -> 'b -> 'c -> 'd) ->
  ('a, 'e) M.t ->
  ('b, 'e) M.t ->
  ('c, 'e) M.t ->
  ('d, 'e) M.tternary f lifts f