eframe error handling (#2433)

* eframe::run_native: return errors instead of crashing

* Detect and handle glutin errors

* egui_demo_app: silence wgpu log spam

* Add trace logs for why eframe is shutting down

* Fix: only save App state once on Mac

* Handle Winit failure

* Log where we load app state from

* Don't panic on zero-sized window

* Clamp loaded window size to not be too tiny to see

* Simplify code: more shared code in window_builder

* Improve code readability

* Fix wasm32 build

* fix android

* Update changelog

crates/egui_glow/examples/pure_glow.rs

@@ -223,9 +223,9 @@ fn create_display(
             height: 600.0,
         })
         .with_title("egui_glow example")
-        .with_visible(false)
+        .with_visible(false) // Keep hidden until we've painted something. See https://github.com/emilk/egui/pull/2279
         .build(event_loop)
-        .unwrap(); // Keep hidden until we've painted something. See https://github.com/emilk/egui/pull/2279
+        .unwrap();
 
     // a lot of the code below has been lifted from glutin example in their repo.
     let glutin_window_context = unsafe { GlutinWindowContext::new(winit_window) };