allow setter functions to be named like With.name With.anotherField

[choonkeat]

when used with options: --prefix '' --module With

import With

increment model =
    model
        |> With.counter (model.counter + 1)

gotName s =
    Maybe.map (With.name s) maybeUser

also added __ suffix to variable names to better avoid name conflicts

[ymtszw]

Cool! And thanks for the patch.
Please wait a while for the release, since I need to do some cleanups.