switch and somes scripts

This switch uses both a switch script to rotate its target : gameobject
around (local to target) direction : Vector3, over duration:float. It
also has a swinging script such that the switch's down vector is always
facing towards gravity. That script requires no setup but has not been
tested on objects with rigidbodys. Additionally, there is my
implementation of a piston and my conveyor belt script. The model is not
working correctly yet, so no prefab