FerroUI main: subscription guards

Ember/app.rs

@@ -49,11 +49,11 @@ impl ApplicationImpl for App {
             // scaled screen (1440 x 940 is 2880 x 1880 pixels at 200 %): the window is then
             // fitted to the work area once it has been placed.
             let weak = window.downgrade();
-            let _ = window.opened(move || {
+            window.opened(move || {
                 if let Some(window) = weak.upgrade() {
                     fit_to_work_area(&window);
                 }
-            });
+            }).detach();
             desktop.set_main_window(Some(window));
         } else if let Some(activity) = lifetime
             .as_ref()

Ember/reader_view.rs

@@ -307,7 +307,7 @@ impl ReaderView {
                         },
                         Duration::from_millis(180),
                         DispatcherPriority::BACKGROUND,
-                    );
+                    ).detach();
                 }
             }
         });
@@ -414,7 +414,7 @@ impl ReaderView {
                 },
                 DispatcherPriority::LOADED,
             );
-        });
+        }).detach();
     }
     fn connect_platform_back(&self) {
         if self.back_handler.borrow().is_some() {