Add a string_scanner package.

This code has been pulled out of the Shelf package.

R=kevmoo@google.com

Review URL: https://codereview.chromium.org//213833013

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart/pkg/string_scanner@34665 260f80e4-7a28-3924-810f-c04153c831b5
6 files changed
tree: b0e09b320b2ba98958d53995f69623f76d18de99
  1. pkgs/