Bo rotation fix

Added proper torque, rotation and attitude handling to base_object.

Torque is applied in units of kg/radians. Rotation is stored in radians/sec. Attitude is in radians between 0 and 2pi. A new rotatable struct was created to store these angles and includes methods to get the angles, or triplets of the sin and cosine. A method is also supplied to properly accumulate rotation due to applied torque.

Unit tested and ready to go.