Doc - Mentioned what the default filters are for       QFileSystemModel::filter().
Doc - Mentioned what the default filters are for
      QFileSystemModel::filter().

Task-number: 250285
Reviewed-by: Benjamin Poulain <3010a403d776cb637ee24d8c14709bb2dc0a154f@nokia.com>
(cherry picked from commit cf65dea821a2ba796bb1f32c80de6b9db224dff5)

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