This replaces "USE_CONFIGURABLE_RGB_VOLTAGE_LEVELS"
with "USE_AUX_THRESHOLD_CONFIG", which controls the brightness of
button LEDs while the main LEDs are on,
and during post-off voltage display.

Same basic concept, but works on single-color LEDs too,
and lets the user finally configure POVD thresholds.

The code for this is a bit messy, but the aux LED code as a whole
is pretty messy since it wasn't designed for the things it does now.
The entire thing needs a refactor or rewrite someday.  But not today.
For now, this is just enough to make the pull request
cover more use cases before merging into trunk.

I've tested it on a variety of lights, but am not yet entirely
comfortable with it.  However, it worked on at least these:
- 1-color button LED, no RGB
- front RGB, 1-color button LED
- front RGB, hardwired also to RGB button
- RGB button, no other aux

These may need extra changes,
and may have extra config options which do nothing...
- front RGB, no button LED
- 1-color front aux, no button LED
- no aux at all
- attiny85 lights (some could theoretically support the new options,
  but none even try)

pulling pr10 branch into a feature branch based on a newer trunk

* 'rgb-voltage-configurable' of github.com:SiteRelEnby/anduril:
  Add a feature to make RGB voltage configurable

so it no longer flashes on each click while advancing to other functions

- changed model number from 0281 to 0171
- cleaned up blink_negative and AUXLED_RGB_DIFFERENT_PORTS a little
  (but the latter needs a complete refactor, as soon as the
   hardware abstraction code can handle aux LEDs better)
- cleaned up USE_LONG_BLINK_FOR_NEGATIVE_SIGN a little
- removed USE_OTG_IN_MOMENTARY since it's not actually used
- moved hw/loneoceans/lume-x1-avr32dd20/* files into hw/hank/lume-x1/
- superficial cleanup on hank/lume-x1/hwdef.*
- removed some of the extra stuff from hank/lume-x1/anduril.h
- adjusted calibration (especially ramp table) on hank-lume-x1
  (ramp shape is pretty close to a D4K-boost now, but with more firefly modes)
  (calibration is based on a sample size of 1, further testing needed)

The [PR](https://github.com/ToyKeeper/anduril/pull/37) has a lot of other
stuff in it, so I'm just picking out the parts needed for this particular
light, and leaving the rest for later.

Will need further edits before merging into trunk.

fixes #85

The Simple UI is meant to be relatively child-safe, and the strobe modes
are not.  Users who want unsafe features enabled should use the full UI
instead... and the strobe + mood modes should also have some safety
features added, on drivers which have enough ROM to hold extra code.

Adds two entries to the battery voltage settings menu, the first
isathreshold for switching aux to high, and the second sets a minimum
level for it to be displayed, also effectively allowing the feature to
be entirely disabled if not wanted.

FIXME: The d3aa's voltage calculator needs to be fixed after this merge.

* trunk:
  use smooth steps in lockout mode, if enabled
  fixed Tactical Mode's strobes when Momentary Mode not enabled
  increased voltage precision from 0.025V to 0.02V (so 0 to 255 now goes from 0.00V to 5.10V)
  fixed inaccurate comment (thanks to xikteny for spotting it)
  Allow manually running GitHub actions workflows
  Bugfix: Prevent switching channel modes when in tactical mode
  Bugfix: Tactical mode has a dependency on momentary mode