hunt for mainline regressions

[Janis Johnson]

My regression hunting is pretty well automated now, but I'm still
figuring out new little tricks and then updating my scripts and
howto document accordingly.  I hope to send those out again soon for
review.

I'm selecting regressions to hunt somewhat randomly from among the ones
for which Wolfgang Bangerth has identified a half-month range when it
occurred.  If you'd like me to search for a particular regression from
his list, let me know.

Janis