w_common

A collection of helpful utilities for use in Dart projects. Right now, it includes the following:

• Disposable interface / mixin to assist with cleaning up streams and other data structures that won't necessarily be garbage collected without some manual intervention.
• A simple typedef that can be parameterized to represent a zero-arity callback that returns a particular type.
• InvalidationMixin mixin used to mark a class as requiring validation.
• JsonSerializable interface to indicate that something can be serialized to JSON.