Object avoidance is possible with just one valid distance
Boundary is initialised in new init_boundary function to be 100m from
vehicle
If sectors do not have valid distance measurements, we use the distance
from adjacent sectors. This conveniently leads to a concave shaped
boundary that keeps the vehicle from travelling into the dataless sector.
Only SF40c uses these ignore areas for now at least.
It is safe to increase the eeprom locations for the 2nd proximity instance because we only define a single instance.