private static String serialiseVersion( BitSet bs )
	{
		StringBuffer sb = new StringBuffer();
		int start = bs.nextSetBit( 1 );
		int end = start;
		while ( end >= 1 )
		{
			int res = bs.nextSetBit( end+1 );
			if ( res == -1 || res > end+1 )
			{
				if ( sb.length() > 0 )
					sb.append(",");
				if ( end > start )
					sb.append( start+"-"+end );
				else
					sb.append( start );
				start = end = res;
			}
			else
				end = res;
		}
		return sb.toString();
	}