Blender Git Loki

New Pulse option for the collision sensor (off by default wont change existing logic)

Previously only the first collision would trigger an event (no collisions a negative event ofcourse)

With the Pulse option enabled, any change to the set of colliding objects will trigger an event.

Added this because there was no way to count how many sheep were on a platform in YoFrankie without running a script periodically.

Changes in collision are detected by comparing the number of objects colliding with the last event, as well as a hash made from the object pointers.

Also changed the touch sensors internal list of colliding objects to only contain objects that match the property or material.

- pulse isnt a great name, could change this.