On Wayland, reduce amount of spurious wakeups

Mark it as breaking, since some clients relied on that behavior, simply
because dispatching clients queue always woke up a winit, meaning that
they won't be able to use user events for this sake.

CHANGELOG.md

@@ -8,6 +8,7 @@ And please only add new entries to the top of this list, right below the `# Unre
 
 # Unreleased
 
+- **Breaking:** on Wayland, dispatching user created wayland queue won't wake up the loop unless winit has event to send back.
 - Removed platform-specific extensions that should be retrieved through `raw-window-handle` trait implementations instead:
   - `platform::windows::HINSTANCE`.
   - `WindowExtWindows::hinstance`.