first v0.2 check-in

long time since I touched this
so far, work has been done on:
* redoing CLI
* making more settings configurable and saved in EEPROM
* general cleanup of code, formatting changes, changing variable type
definitions

goals
* cleaner mode switching and ensuring motors never come on unless
explicitly told to and shut off immediately in any panic situation
(safety)
* configurable everything
    - battery monitor - voltage/current scaling and offset
    - motor - pwm frequency, min and max throttle
    - load cell - calibrations
    - tests - defined length of time
        - primary test - ramps motor up, holds at max throttle, ramps
down - length of time for each ramp/hold configurable
        - response test - set throttle to some level, change it by a
large amount. repeat several times with several amounts, all
configurable
        - hover test - searches for half throttle then holds there for
a configurable amount of time.

There's a ways to go with this but I'm hoping to have it way more
useful by the end of the year.