Use 'Directory.watch' on Windows in pkg/watcher, instead of pooling.

This is a close copy of MacOS, except for the special handling on mac, and the extra watcher on Windows for detecting if the watched folder is deleted.

BUG=https://code.google.com/p/dart/issues/detail?id=14428,https://code.google.com/p/dart/issues/detail?id=18108,http://code.google.com/p/dart/issues/detail?id=19189
R=kasperl@google.com, sgjesse@google.com

Review URL: https://codereview.chromium.org//312743002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart/pkg/watcher@36988 260f80e4-7a28-3924-810f-c04153c831b5
4 files changed
tree: 930a858e8681f021f807b283d2cd18122a937600
  1. pkgs/