Partial API sketch, dart:io and dart:html implementations.
More work on lib/html.dart
Remove dart:io import, add some html.dart tests.
Add path, openWrite, and rename tests. Rename IOSink to FileSync
Make tests independent of implementation, run them on IoFilesystem.
move path to the parent class
Merge pull request #1 from devoncarew/devoncarew_move_path

move path to the parent class
Merge pull request #2 from justinfagnani/work

Move work to master