Add a mode property to QMenuBar for Windows CE/Mac

It appears that menu bars can have modes:

• Mac: global menu bar for all app windows (construct with 0-parent)
• Mac: local menu bar
• Windows CE: CE global menu bar
• Windows CE: Qt-style menu bar [not implemenred]
  There might be others on different platforms.

Now, instead of hacking the Mac case into Designer (as the parent task suggests), would it be possible
to add a mode property to QMenuBar? - It should have a well-defined default:

• DefaultMode
• MacGlobalMode
  ..
  or such?