self destructing label

if we don't have label prims, the script cleans itself up; mouse found a
clever solution to determine if we have label prims for this case;
unfortunate is that the label text on the default collar design is
slightly off center but that was always the case for any other collar
design that had labels smaller or greater than a dozen characters and
weren't using tortured cylinders; otherwhise the same as stated in #254