Use fcl for geometry

  - remove dependency to
     - Kitelab and
     - jrl-dynamics
  - add dependency to fcl,
  - implement class Body as fcl::CollisionObject container,
  - implement forward kinematics.
Update documentation
Fix doxygen link between pointers and types.
Cosmetic changes

  - clean up code (remove #if 0 blocks)
  - add documentation.
Extend use of Eigen::Ref to input/output vectors and configurations.
Use typedef for refering to Body and Joint pointers.
Return const reference to JointPtr_t instead of const JointPtr_t.
Remove const qualification for joint_ member of collision object.
Enforce coding style.

  Setter and getter have the same name as the member.
Implement copy of joints.
Implement copy of joints

  - copy body and collision objects.