Add SODAR

Just some refactoring for pulling the LED only loop out and getting the robot loops set up for SODAR as well.  Since we're using two sensors, I figured we wouldn't need for it to be as modular as the LedArray.

This really only adds the support for the SODAR sensor to initialize and get the distance in centimeters.

Moving forward, we need to add to the loop what to do when certain scenarios are encountered and we'll likely need a bit of history to keep track of the distance between the walls and the robot.

Thoughts?