_inertial_state is now updated to reflect the height as measured by the ir and sonar sensors.
Merge branch 'v2' into v2-z-is-height
Turned the sensor selection code into a state machine in an attempt to prevent hysteris. Add the nessecary calls to main to start the adc.
Merge pull request #7 from PSU-AVT/v2-z-is-height

V2 z is height