Revert "Enable Lion-style fullscreen mode for Creator."

Breaks with Qt 4.7.

This reverts commit f27a916024.

Change-Id: I52e64dbd0e1602d400c83e32f4c8e2cf81d88d3f
Reviewed-by: Daniel Molkentin <daniel.molkentin@nokia.com>

src/plugins/coreplugin/mainwindow.cpp

@@ -225,11 +225,6 @@ MainWindow::MainWindow() :
      //signal(SIGINT, handleSigInt);
 #endif
 
-#ifdef Q_WS_MAC
-    extern void enableMacFullScreen(WId);
-    enableMacFullScreen(winId());
-#endif
-
     statusBar()->setProperty("p_styled", true);
     setAcceptDrops(true);
 }