Fix bug in Element DisplayMode calculation not accepting HIDDEN.
Fix bug in Element DisplayMode calculation not accepting HIDDEN.

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