When a window is being dragged, we prevent delivery of clicks to Wine.  We were
also preventing telling Wine that a window had been brought forward, but this
was incorrect.  It prevented clicks in the title bar from activating the window.

winemac: Track which window was brought forward by Cocoa separately from the window receiving the click event.

If the mouse is captured, we change which window receives the click event, but
that shouldn't change which window we tell Wine was brought forward by Cocoa.

We can't prevent Cocoa from bringing disabled/no-activate windows forward.  So,
we need to tell Wine about the z-order change.

We still do avoid telling Wine to activate disabled/no-activate windows, though.