Fix some levels; reorganize some algorithms

- Now that it's been used
- Include the blinkingness in LEDS_FOR_LEVEL
- Change and add levels to match historical Rock the Bike pedalometers
- Generalize the data and code over both rails
- Rename "ledsState" to "level", because that's what it provides
- I'll split the levelVolts and LEDS_FOR_LEVEL by rail