The closure passed to `eframe::run_native` now returns a `Result`,
allowing you to return an error during app creation, which will be
returned to the caller of `run_native`.
This means you need to wrap your `Box::new(MyApp::new(…))` in an
`Ok(…)`.
* Closes https://github.com/emilk/egui/issues/4474
* Detect panics during initialization and show them to the user
* PanicHandler now also logs the panics
* Add example of how to call into your app from JS
* Refactor: break out AppRunner and AppRunnerRef to own files
* Hide AppRunner
* Simplify user code
* AppRunnerRef -> WebRunner
* Better docs
* Don't paint until first animation frame
* Update multiple_apps.html
* Update web demo
* Cleanup and fixes
* left-align panic message in html
* Refactor: remove extra store of events
* Remove unnecessary extra function
* Refactor: simplify event registering
* Store panic summary
* egui_demo_app: move web-part to own module
* index.html: await
* Properly unsubscribe from events on panic
* Better error handling
* Demo app html: hide the wasm canvas and show an error message on panic
* egui_demo_app: add panic button to test panic response on web
* fix typo
* Use a constructor to create WebHandle
* Refactor: less use of locks in the interfaces
* More consistent naming