Some cleanups and improvments made while trying to track down this crucial
last (known) bug before release...  Then there's a few minor regressions
to take care of after that, but this is the make-or-break bug for
releasing next weekend.
OK, I think it's getting close now...  1 more bat-shit-crazy concurrency
issue to go (which I already know how to fix) and I think the 2.0 release
is a 'go'...