* Standard clone methods now cause an exception in RobotNodes in order to prevent user from doing nasty/errornous things.
 * Set global pose of cloned objects.
 * Implement _clone method in objects that derive from SceneObject in order to return correct instances when cloning.
Convenient helpers:
 * Methods for easily setup a united set of objects. (This can drastically improve collision detection in case static obstacles are present)
Improvements
 * Improving datapath search in order to cover most likely path setups.
 * Switching to asserts in core collision detection routines in order to avoid lots of checks in release builds.
 * Add manipulability measure for directed movements.
 * Billboard support for Coin3D visualizations.

git-svn-id: http://svn.code.sf.net/p/simox/code/trunk@259 042f3d55-54a8-47e9-b7fb-15903f145c44