Update the servo pin definition for the latest boards
Put a basic framework in place to be able to do line following, collision detection and sound (only beep at the moment though)
Initial untested stab at the addon code
Store the hardware version in EEPROM

So we can make sure to send out the correct firmware updates at a later date.
Also, add commands for setting it and querying it.
Use timer1 for the stepper driver
Get the collision detection working for real
Finalise the line following code