Toradex and xtion shutters

Start toradex node by:

$ rosrun toradex toradex_node

Start xtion multiplexer by:

$ rosrun toredex switch_node in1:=/xtion1/depth/image in2:=/xtion2/depth/image ...

Start multiplexing by sending a message:

 $ rosservice call /desired_shutter "shutter:
  shutter1: true
  shutter2: true
  shutter3: false"