Horizon Sensor Heads.

August 2008  C Gumbrell

New sensor heads. 'IR_Horizon_Sensor_Head'
Contains both IR and visible sensors.

V10 - original design. Never manufactured
V11 - added amplifiers etc. This is the manufactured version.
      This version was incorrectly labels V1.0 on the PCB!

16 March 2009

Renames files from IR_Horizon_Sensor_Head to Horizon_Sensor_Heads, because the 
files in fact describe both sensor heads.
V11 only.