Move a number of packages and some of pub over to using source_span.

R=efortuna@google.com, rnystrom@google.com, sigmund@google.com
BUG=19930

Review URL: https://codereview.chromium.org//401753002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart/pkg/string_scanner@38526 260f80e4-7a28-3924-810f-c04153c831b5
6 files changed
tree: 03f7febaf126fe762d6f0232dd2b3c33c3524c6a
  1. pkgs/