robot-model: recipes added.

robot_model contains packages for modeling various aspects of robot
information, specified in the Xml Robot Description Format (URDF). The core
package of this stack is urdf, which parses URDF files, and constructs an
object model (C++) of the robot.

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RECIPES collada-urdf AND kdl-parser
OF THE ROBOT-MODEL PACKAGE HAVE NOT BEEN ADDED YET.
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