Added ability to get/reset encoded motor positions

Some students asked for the getEncodedMotorPosition to work, so I added it. It led to a minor rewrite of how the moveEncodedDCMotor() works in the firmware, so check it out. I tested it on a working robot, and it works.

Also, I added to the firmware folder a zip file with the libraries needed to compile in the Arduino IDE. I figure this would be a good addition for future generations.