changes to how to run rviz with the real youbot

meaningless changes, but this was what was working for me on 12/26/2013
rotated xtion 360 degrees

The WPI-RAIL version of the youbot description had the xtion camera
facing in the opposite direction from the gripper. That's not how we
intend to use it, so here are updated xacro, urdf, and moveit config
files.
included sensor manager code

finally got the xtion point cloud working in the moveit config.