(from the patch which is included)

    jigdo-lite: parallel wget download if xargs is available

    Jigdo downloads are significantly slower than iso downloads because there is
    a new connection between each file, with a pause. This slow-down is greater
    the faster the connection, so wouldn't be that big with a 56kbps connection,
    and has increased since this software was developed.

    No change if "xargs" from "findutils" is not available.

    There is still a pause, yet to be removed, when commiting each batch of
    files to the iso9660.

    Signed-off-by: Shawn Paul Landden <shawnlandden@outlook.com>