Svelte #73
Description
DomWrapper needs to track all state changes so cloneNode() can be implemented. This is because VisualElement doesn't have any serialization built-in. We'll need to take care of deep cloning from scratch. Svelte uses fragment + cloning for creating new components under-the-hood.
Svelte's handle_event_propagation() will need to be majorly patched so the event obj won't be mutated. WeakMap and Proxy will be needed. Proper dispose on engine reload will need to be looked into as well.
TextNodes (especially when used with <button/>) need more work.
More polyfills as we discover them.