Update docs regarding sibling widgets ontop of QGLWidgets when Qt is built with Cocoa support on Mac.
Update docs regarding sibling widgets ontop of QGLWidgets when Qt is built
with Cocoa support on Mac.

The Cocoa API doesn't have a concept of Z-ordering of widgets, and it's
implemented by reordering the widget hierarchy for normal widgets. This
does unfortunately not work for GL widgets, and it's not supported by
Apple. This apparently work with the Carbon AGL API though.

Task-number: 244890
Reviewed-by: Gunnar Sletta
BT: yes

igor-sfdc/qt-wk,pruiz/wkhtmltopdf-qt,radekp/qt,radekp/qt,KDE/qt,radekp/qt,igor-sfdc/qt-wk,RLovelett/qt,pruiz/wkhtmltopdf-qt,RLovelett/qt,igor-sfdc/qt-wk,KDE/qt,KDE/qt,radekp/qt,pruiz/wkhtmltopdf-qt,pruiz/wkhtmltopdf-qt,pruiz/wkhtmltopdf-qt,radekp/qt,radekp/qt,pruiz/wkhtmltopdf-qt,pruiz/wkhtmltopdf-qt,RLovelett/qt,radekp/qt,pruiz/wkhtmltopdf-qt,RLovelett/qt,KDE/qt,igor-sfdc/qt-wk,igor-sfdc/qt-wk,RLovelett/qt,RLovelett/qt,RLovelett/qt,KDE/qt,RLovelett/qt,pruiz/wkhtmltopdf-qt,RLovelett/qt,radekp/qt,igor-sfdc/qt-wk,KDE/qt,igor-sfdc/qt-wk,radekp/qt,igor-sfdc/qt-wk,KDE/qt,igor-sfdc/qt-wk,igor-sfdc/qt-wk,igor-sfdc/qt-wk,RLovelett/qt,pruiz/wkhtmltopdf-qt,RLovelett/qt,radekp/qt,pruiz/wkhtmltopdf-qt,KDE/qt