Convert shelf to use the string_scanner package.

This also adds support for [StringScanner.error], which produces a
nicely-formatted scanning error.

R=kevmoo@google.com

Review URL: https://codereview.chromium.org//222843003

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart/pkg/string_scanner@34669 260f80e4-7a28-3924-810f-c04153c831b5
4 files changed
tree: b68f910692fff5688b2bc808e0febc4947330691
  1. pkgs/