Furnish new ball-park benchmark numbers

I now think I understand why the 10MB file test was *so* slow,
although it did not occur to me at the time: S3-Classic/US-Standard
may opt to home keys across the continent from one's instance, and
this does not seem to converge over time (e.g. through mirroring).
So, this can be re-cast as a "slow link" test.  It seems this can
happen if one uploads to S3 from a place geographically closer to
Seattle, unless one uses the s3-external-1 endpoint.  I uploaded the
test file from such a location.

Knowing this, I tried another small key made from within EC2 us-east.
This has become my new benchmark for "the very fast and very small"
pathological case.

Most mysterious is Amazon CloudFront: I cannot get it to perform well
with htcat at all, although it's offering excellent curl performance.
It's not even abundantly clear that slower processing of Range
requests is the whole story: I'm still baffled by the stark nature of
the results and a few other bizarre observations.