[pocolibs] Fix an bug in rflex_overlays: list does not have clear() method
[pymorse] Improve port error handling

When a component has a datastream that is not socket, the
get_stream_port service now fails. This failure is correctly handled by
pymorse that does fail on creating the associated Stream.
PR2 can grab object as human does.
[laserscan] do not show arc in 2.66

BGE bug was fixed on rev. r55483 by Dalai Felinto
http://projects.blender.org/tracker/?func=detail&aid=34550
Should be OK in 2.67 - fix #304
Created a grasper robot with RobotGrasper class.

This class just define an abstract robot with the grab_ service.
The main goal of this class is to avoid code duplication.