diff_steer effector

Provides a simple simulation of a differential steer drive system. It is throttleable, reversible and has a separate braking function. Power and braking max limits are configurable in newtons, the turn rate in radians/sec.  The exposed interface accepts turn, power and braking settings as percentages for simplicity of operation. 

Unit tested for simple forward, braking and turning, as well as a compound drive/turn test. All passed and all produce the expected numerics.