Use generic name for the robot instance. This enables users on the script commandline (eg. ipython) to run the same commands without asking them to specifically tell what robot they're using (eg. hiro, nxc). This is backward compatible so that users can still keep using `nxc`. See http://code.google.com/p/rtm-ros-robotics/source/detail?r=6926 for hironx.

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