Queries can be run out of order because the main thread is waiting on the
response.  The main thread didn't really need a response from QUERY_RESIZE_END.
It was only a query for symmetry with QUERY_RESIZE_START.

The Mac driver was already sending these events when the user resizes the
window by dragging its corner/edges, but there are other occasions when the
window frame changes.  For example, when the user zooms the window.

This seems to eliminate a lot of house-keeping work inside Cocoa.

comctl32: Initialize treeview checkboxes in WM_PAINT when TVS_CHECKBOXES was passed during control creation.

The tracking of whether it is over a window or not is only updated when the
mouse moves.  If a window was created or moved under it, then the state can be
stale.  That caused us to defer hiding the cursor until the mouse was moved.
This happens at the start of games pretty often.

winemac: Don't use the main dispatch queue to implement OnMainThread() for a thread with no event queue.

The main dispatch queue is a serial queue and is a shared resource.  If we
submit a long-running task to it, then no other tasks, including those submitted
by the system frameworks, can run until it completes.