Remove livecd-tools group
    
    I am about 99% sure nothing uses this any more and hasn't for
    a long time. I checked fedora-kickstarts and pungi-fedora. I
    think this stopped being used when we switched to livemedia-
    creator, as syslinux was added to fedora-live-base.ks at that
    time.
    
    Signed-off-by: Adam Williamson <awilliam@redhat.com>