- add inline function to normalize a configuration.

  - notify copyright outside doxygen,
  - remove obsolete tags.

  - std::size_t is the type of standard container index,
  - size_type is the vector and matrix index.

  they might differ (int for Eigen, and unsigned int for std).

  - remove dependency to
     - Kitelab and
     - jrl-dynamics
  - add dependency to fcl,
  - implement class Body as fcl::CollisionObject container,
  - implement forward kinematics.