Option to loop through the gallery

[muiradams]

Currently when the user gets to the end of the gallery the next button disappears, and the user is unable to return to the first item without either going back through all the slides, or closing it and clicking on the first slide. Our user testing showed that if they aren't paying attention, and don't notice that the next button disappeared, then clicking where the next button used to be closes the modal. While this is the expected behavior, it can be confusing and provide for a negative user experience. It would be nice to have the option to turn on looping with the gallery, where once the user gets to the last slide they are able to click next again to loop around to the first slide. Conversely, if a user is on the first slide and clicks previous they should be able to get to the last slide.