update to Dart 1.0

Hey,

I updated your library to work with Dart 1.0. I would be very happy if you would pull from my branch and update the package on Pub. If you disagree with some commits I made (the last one that removes trailing white spaces can be somewhat controversial among certain people) I can take it back.

There is another fork from about 10 days ago that tries to do the same, but only a little work  has been done there, so I would suggest you take my change.