fix QTextFormat::doubleProperty where qreal is float
fix QTextFormat::doubleProperty where qreal is float

This function was too strict. It returned 0 if the property wasn't of
type QVariant::Double. Now it tests for QMetaType::Float too.

Reviewed-by: kh1
Reviewed-by: mauricek

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