Fix some qdoc-warnings.

qtbase/src/widgets/kernel/qaction.cpp:1257: warning: Can't link to 'QApplication::setAttribute()'
qtbase/src/widgets/kernel/qapplication.cpp:519: warning: Can't link to 'arguments()'
qtbase/src/widgets/kernel/qapplication.cpp:1939: warning: Can't link to 'quit()'
qtbase/src/widgets/kernel/qapplication.cpp:2946: warning: Can't link to 'quit()'
qtbase/src/widgets/kernel/qapplication.cpp:2946: warning: Can't link to 'exit()'
qtbase/src/widgets/kernel/qapplication.cpp:2946: warning: Can't link to 'processEvents()'
qtbase/src/widgets/widgets/qmenu.cpp:1354: warning: Can't link to 'Recent Files Example'
qtbase/examples/widgets/doc/src/tetrix.qdoc:28: warning: Can't link to 'QApplication::quit()'
qtbase/src/testlib/qtestcase.cpp:268: warning: Undocumented parameter 'timeout' in QTRY_VERIFY2_WITH_TIMEOUT()
qtbase/src/corelib/global/qnamespace.qdoc:2427: warning: Can't link to 'QApplication::setLayoutDirection()'
qtbase/src/corelib/global/qnamespace.qdoc:751: warning: Can't link to 'QApplication::setDesktopSettingsAware()'

Change-Id: Ic8170a40fb1cd84e3fb4dd75d9429f4b485f8bd9
Reviewed-by: Martin Smith <martin.smith@digia.com>