pkg/watcher: prepare for 0.9.3

added changelog
updated pubspec
code formatting
removed unused imports

R=ajohnsen@google.com

Review URL: https://codereview.chromium.org//441483004

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart/pkg/watcher@38862 260f80e4-7a28-3924-810f-c04153c831b5
21 files changed
tree: 525d2779e1c4fe90690e99b67117309c35c7f40f
  1. pkgs/