Fail to calibrate prismatic joint

[pazeshun]

[pazeshun]

Two causes:

• Multi turn mode of motor is sometimes wrong
  • Careful debugging will solve this. -> Fix calibration of prismatic joint #2566
• Motor sometimes detects high torque when prismatic joint moves heavy load (eg. hose and gripper itself)
  • Adding touch sensor will solve this. Takes long time.

First, I have to solve the former cause.

[pazeshun]

The former cause may be fixed.
I'll solve the latter cause.