QDirIterator: Doc fixes and whitespace cleanup
QDirIterator: Doc fixes and whitespace cleanup

There is no QDirIterator::isValid() function.

Reviewed-by: David Boddie

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