[Bug 40090] Window frame icon missing with MacDriver

https://bugs.winehq.org/show_bug.cgi?id=40090

--- Comment #3 from Ken Thomases  ---
Really, we need to make winecfg have a widget to select the user driver and
then have separate sets of controls appropriate to the selected one.  I'm just
too lazy to do that.

In part, the behavior of Cocoa and the Mac windowing system is much more
predictable than the nearly infinite variety of desktop environments and window
managers on other platforms.  Therefore, I think the Mac driver is more
reliably correct than the X11 driver.  So, there's much less need to disable
window decorations or the like.