Update Examples/elm-yesod to better match online interactive examples
see http://elm-lang.org/edit/examples/

index.elm
    remove "box" fns (obsolete)
    disambiguate "link" fns (Text or Graphics)

tested against ghc-7.4.1, Elm-0.7.1.1, yesod-1.1.7.1, elm-yesod-0.1.3
Update Examples/elm-yesod: bump downloaded elm-runtime version from 0.3.5 to 0.7.2 (latest)

tested against ghc-7.4.1, Elm-0.7.1.1, yesod-1.1.7.1, elm-yesod-0.1.3