A number of bug fixes in response to yesterday's email

Fixed arm lidar, changed Wrench to WrenchStamped for force torque sensors, modified front bumper collision, modified wheel friction parameters, changed camera color, added teleop package for easier push to Technion, modified IMU and GPS sensors for integration with robot_pose_ekf.

More coming, from now on I'll try to do one per pull request so that they're easier for you to keep track of.