1.0.0: Milestone for API stability

A major milestone with the commitment of API stability and forward compatibility for future releases.

What's new?

• More intuitive API for complex state binding: State-derived properties and State-derived child nodes
• Unified API for derived states, side effects and advanced derivations: van.derive
• NPM support
• Supports null as a valid property value for tag functions
• More graceful behavior for invalid property values provided in tag functions
• More graceful behavior if an error is thrown in the binding function
• A new demo application: package-lock.json inspector (in 28 lines)
• Performance optimizations

See the release announcement: #72