2010-04-01      v.0.002
  - Added vars() method.
  - Updated docs.
  - Removed AUTOLOAD behavior from Widget and Linker.
  - Added $widget->get( $attr ) and $widget->set( $attr => $value )
  - Added $widget->on_change( $attr => sub { ... } )
  - Added several tests.

2010-04-01      v0.001
  - Initial release.
  - No joke!