Switch pkg packages, pub, and dartdoc to use package: imports.

This also changes the SDK layout by replacing the "pkg" directory, which
contained the full source of all the packages needed by pub and dartdoc, with a
"packages" directory that contains only their lib directories. This directory is
used as the package root for pub and dartdoc when run from the SDK.

BUG=6745

Review URL: https://codereview.chromium.org//12782016

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@20640 260f80e4-7a28-3924-810f-c04153c831b5
10 files changed
tree: 92a3d1244da9ce810ed42de3b51d96bc1a0fa5dc
  1. lib/
  2. test/
  3. pubspec.yaml