Make error handling optionally more permissive. (dart-lang/package_config#58)

* Make error handling optionally more permissive.
* Make the LanguageVersion be an object, not a string.
* Make it version 3.0.0-dev
15 files changed
tree: 6bc05df936348f72719b59e85684f3ee34a5ee5f
  1. pkgs/