Initial support for resistance lookup table
Forgot to decode the value from the resistance table (just subtract 50)
Estimate table values at the limits of resistance adjustment.

These need to fall outside the regular 1-100 resistance range
in order to maintain a vaguely correct slope when interpolating
near the edges of the table.

Table values to be refined further when more data collected.
Initial support for bilinear interpolation.

Code could use some cleanup but appears functional when called
from test harness.
Minor tweaks to interpolation routines
Update lookup table with revised values
Add inital support for calibration mode. Update ergo mode
to use lookup table instead of calculated resistance.
Comment cleanup
Small tweaks to resistance table values
Minor update to the speed averaging