v0.16.0

Big changes to experimental features:

• New resource API createResource and createResourceState to replace loadResource. These are built to prioritize read capabilities and simplify implementation.
• Support for Async SSR renderToString now returns a promise. Uses Suspense to know when it is done.
• Progressive Hydration with code splitting support. Ability to track events and replay as hydration completes to reduce "uncanny valley". Components can be lazily loaded even during hydration. No support for async data on hydration yet, so render it from server and load into state synchronously.
• New error boundary api with onError. If an error occurs in context or child context the nearest handler/s will be called.
• Deprecating the force setState modifier as it is confusing.