WIP: Resolve "Processor constructors and creators requiring a sensor pointer?"

Closes #248 (closed)

demos/processor_odom_3D.yaml

 type: "ODOM 3D"              # This must match the KEY used in the SensorFactory. Otherwise it is an error.
-name: "Main odometer"        # This is ignored. The name provided to the SensorFactory prevails
 
 time_tolerance:         0.01  # seconds
 unmeasured_perturbation_std: 0.001