instead of -1.

  when checking sizes of vectors.

  - remove unused variable.

  - use GJK algorithm to detect collision between triangles.
  - Remove methods
    - MeshCollisionTraversalNodeOBB::leafTesting,
    - MeshCollisionTraversalNodeRSS::leafTesting,
    - MeshCollisionTraversalNodekIOS::leafTesting,
    - MeshCollisionTraversalNodeOBBRSS::leafTesting,
    use parent class implementation instead.

  - old constructor is deprecated.

  - store const CollisionRequest& as a member instead of CollisionRequest,
  - remove member CollisionRequest::enable_distance_lower_bound,
  - modify constructors of all derived classes.

  - overlap method without sqrDistLowerBound as an argument call the method
    with sqrDistLowerBound as an argument.

  Simplex::c -> Simplex::vertex.
  Simplex::p -> Simplex::coefficient.

  - security_margin is the distance below which collision test returns
    collision,
  - break_distance is the distance below which bounding boxes are broken
    down.

  void collide(CollisionTraversalNodeBase* node, FCL_REAL& sqrDistLowerBound,
               BVHFrontList* front_list) ->
  void collide(CollisionTraversalNodeBase* node,
               const CollisionRequest& request, CollisionResult& result,
               BVHFrontList* front_list),
  void propagateBVHFrontListCollisionRecurse (CollisionTraversalNodeBase* node,
                                              FCL_REAL& sqrDistLowerBound,
                                              BVHFrontList* front_list) ->
  void propagateBVHFrontListCollisionRecurse (CollisionTraversalNodeBase* node,
                                              const CollisionRequest& request,
                                              CollisionResult& result,
                                              BVHFrontList* front_list)

  - void selfCollisionRecurse(CollisionTraversalNodeBase* node, int b,
                              BVHFrontList* front_list),
  - void selfCollide(CollisionTraversalNodeBase* node,
                     BVHFrontList* front_list).

  - warning; this diagram is built by hand and may be incomplete.