Fix FLOW grammar to make attributes truly behave like optional
Fix FLOW grammar to make attributes truly behave like optional

foam-framework/foam2,foam-framework/foam2,jacksonic/vjlofvhjfgm,foam-framework/foam2,jacksonic/vjlofvhjfgm,foam-framework/foam2,foam-framework/foam2,jacksonic/vjlofvhjfgm