Added mode to Portfolio widget

Created by: HaakonME

The Portfolio widget has three modes, the default mode being "modal", while "card" and "orbit" are the two other modes. [var=mode]orbit[/var] in a layout will indicate an image carousel, [var=mode]card[/var] will indicate a card layout with a bit of shadow below each card, while modal lets a user click on an image and get a full-screen version.