[Regression] Mac: QMessageBox style

Compared to Qt 4.6.x-4.8.x, QMessageBox has changed dramatically in Qt 5.0 (no style sheets applied):

• message icon became smaller (what that intended? I don't think it should be)
• main (message) text and informative text style doesn't correspond to Apple HIG
• dialog titlebar contains title text, while according to Apple HIG should not be present for (as they call it) alerts
• instead of close titlebar button, maximize button is enabled (but does nothing when clicked)

I've attached 2 screenshots (Qt 4.8 vs. 5.0) for comparison.