Lightbox/modal multi image improvements

• Navigation arrows do not appear until you move your mouse. This is really bad, especially on mobile as it requires you touch the screen but it's difficult to do this without exiting the lightbox

• Possible to allow swipe gestures or click/drag to navigate between the items? This would be a huge improvement for mobile

• Visible button on the screen/image to exit the lightbox. On mobile with large portrait images you have to touch the thin area in the background (status/timeline) to exit the image.