* Migrate most of the old tests over
* Replace croak with throw
* Redo error handling
* Test errors

* Ship with ysh!

* Don't ship with Spiffy -Base filtering. (use -base)

* Support this cruft:

    @EXPORT_OK = qw(
                    VALUE COMMENT
                    Bless Blessed
                   );

    use strict;
    use YAML::Node;
    use YAML::Transfer;
