Mark reused buffers as busy before returning from nextBuffer (before,
they only got marked busy on init).
Re-attach wl_buffer listener after re-initializing a buffer. This lets
the re-inited buffer still get a released event.
Combine scale and translate matrices with multiply instead of overwriting
Use appendAssumeCapacity for pixel conversion loop (since we already
initialized the list with the correct size).
This actually renders a wallpaper for each output using the newly added
Buffer and BufferPool for shared-memory surfaces and creates a
wlr-layer-shell surface per output. Right now, each wallpaper
shares the same wallpaper (though scaled to each).
wl_output globals get added to a HashMap that is used by Output when it
gets an output event.
Fix null-safety in WindowManager when no seats/outputs exist and route
Window dimensions through pending_manage.
