Added a joystick controller of end-effector in Cartesian space:
  usage is like: scripts/teleopCart.py _joy_kind:=RS
  use launch/switch_joy{,2}.launch, you can execute the original lfd_teleop_joystick2 and teleopCart simultaneously and select one of them by R2 button
  modified src/moveUtils.py, src/cartesianTrajIK.py for this purpose

Modified src/recordInteraction.py:
  added a command (press the left stick button of the joystick) to stop the interaction

Modified src/bag2mat.py:
  now, it asks to the user if it fails to figure out which the file is controller or mannequin (i.e. controller_num==mannequin_num)
  such a situation happens in recording a demo with the non-interaction mode (e.g. the arm is controlled by a joystick)
  fixed a bug: getMatrixRow* fails if currTopicVals contains valid messages, so added a code to skip the data in that case
  fixed a bug: added a code to do nothing if no samples are collected

Modified scripts/processDemos.py:
  now, it asks to the user if it fails to figure out which arm the part is from (i.e. left_num==right_num)

Modified src/dmpExec.py to work without moveUtils::commandARHeadTrack