www/dezoomify-rs: Add new port
dezoomify-rs is a tiled image downloader. Some webpages present high-resolution
zoomable images without a way to download them. These images are often tiled:
the original large image has been split into smaller individual image files
called tiles. The only way to download such an image is to download all the
tiles separately and then stitch them together. This process can be automated
by a tiled image downloader.