Full sized images for lightbox

With the modified code, the lightbox will show the original image file instead of a smaller version. We store the original image on our servers but only use scaled-down versions? That looks strange to me, so i decided to let the lightbox show a hight resolution version of every image.

If an image is too big for the screen, it will be scaled down dynamically by CSS.

Corresponding post on loom.io: https://www.loomio.org/d/95wh18Lt/high-resolution-full-sized-images-for-lightbox