Use grasp detector in grab.py

[PetervDooren]

trafficstars

implemented and tested on the robot. This also required re-tuning the grasp detector. It is now a bit conservative and it will not be able to detect objects of less than centimeter across.

The max torque was changed to 1 to match what is used in grab.py and hero-close-gripper. Changing this value also meant the minimum position had to be changed.