Obtains a list of URLs associated with a resource by quering a registry
server, then downloads and packages all the source files. The collection
of files is packaged into a zip file and written to the output stream.
Generate an image of a QR Code which will jump to the download of a resource.
It accepts the same arguments as downloader, plus size information for the
generated image. The default size for an image in 150x150 pixels.