Fixes T5500. When an image is embedded with {Fxx, size=full}, add "max-width: 100%;" so that large images are scaled down to the size of the container. This seems like a better and more reasonable behavior than having them scroll. You can still lightbox them or right-click -> view if you really want the full image.

Dragged window around with a very large size=full image. At large window sizes, the image displayed at 100%. At smaller window sizes, the image was scaled to fit.