Having two large numbers separated by a dash can make visual
comparisons difficult when numbers are in the 3,000,000 range
for LKML. So avoid the $UID_END value, since it can be
calculated from $UID_MIN. And we can avoid large values of
$UID_MIN, too, by instead storing the block index and just
multiplying it by 50000 (and adding 1) on the server side.
Of course, LKML still goes up to 72, at the moment.