It's the same as &hank-emisar-d3aa, but needed some minor tweaks:

- wait longer before measuring the battery,
  because it's hard to tighten the tailcap fast enough

- ramp adjustments to compensate for slightly different "gear ratio"

After testing on every device I can, and getting several users to also
test this, it appears to reduce and sometimes completely eliminate
preflash on most devices... and the cases where it wasn't reported to
help, at least it didn't make things worse.  Some units apparently just
can't get the flash eliminated completely, despite trying lots of things.

Instead of turning the chips on and then waiting 4ms, it now turns the
preflash absorber on, waits ~0.6ms, sets misc params, then turns the
boost chip on, then waits ~0.6ms, then turns the preflash absorber off.

This seems to work best on li-ion power, where on my devices it completely
eliminates any preflash.  There is still a very mild flash on AA though,
which I wasn't able to get rid of.  But it's like... 0.003 lm for just
a few milliseconds, really not bad.  Even in the worst case reported by
a user, based on the video they took, it looks like just 0.01 lm for
a few milliseconds.

(also, fixed bug where a totally empty li-ion didn't get limited)

and not letting the magic smoke out of updi adapters any more (probably)

The alkaline detection might be a little too lenient though; it
could potentially fail to activate limits when the cell is completely
full or stronger than an average alkaline.  One of my test cells
measured at 72 / 75, so if it was just a little stronger it'd pass...
but most alkalines I tried were in the 40 to 60 range and failed easily.

OTOH, if I make it easier to fail, it's likely to trip on normal li-ion
cells, and I don't want that.

So as a future enhancement idea, maybe it should have a smaller sag
threshold for AA and a larger threshold for li-ion.  That would reduce
false negatives for AA, while still preventing false positives for li-ion.

(saving progress here so I can work on a different branch)

- new ramp
- production style config defaults (simple mode, Hank config)
- candle tuning
- fixed way-too-fast thermal regulation
  (might still be a bit fast, but it's a lot better)