Minor cleanup by Tim after my changes:

Minor cleanup by Tim after my changes:

+ Took the "list" argument out of the other functions that no longer need
it.  This speeds things up a little more.

+ Small comment changes in accord with that.

+ Exploited the now-safe ability to cache values in the partitioning loop.
Makes no timing difference on my flavor of Pentium, but this machine ran out
of registers 12 iterations ago.  It should yield a small speedup on a RISC
machine, and not hurt in any case.