Feature/arduino upgrades

[danic85]

Some general improvements and callibration of the arduino script. Includes a couple of modes when certain pins are set to ground (with switches etc):

• Pin 12, enables 'backpack mode' which will straighten the legs so that the robot can sit in a small backpack with the head sticking out and animating. Legs will not move past initial position, even with signals from Pi.
• Pin A1, enables 'restraining bolt' mode which prevents legs from moving from starting position, even with signals from Pi.