Merge pull request #92 from vbychkovsky/master

Getting elm-happstack to work... [ still broken ]
Add type annotations to Either.
Fix a messed up type annotation in Dict.elm.
Update the list of built-in modules.
Merge branch 'master' of https://github.com/evancz/Elm
Add type annotations to the Set library.
Properly resolve cyclic dependencies.
Merge https://github.com/evancz/Elm