Position of octree is defined by resolution only. cell center coordinates are
  of the form:
    ((kx+.5)*resolution, (ky+.5)*resolution, (kz+.5)*resolution), where
    kx, ky, kz are integers.
  This commit fixes the construction of the environment octree in order to
  respect this constraint.
  In test_fcl_octree, envOctree contains envMesh.

  If GJK returns fail, assume no collision.
  Fix computation of closest points.

  to check that if no collision lowed bound of distance is positive.

  sqrDistLowerBound output parameter was not computed.

  - if collision is very small epa algorithm may return slightly negative
    penetration.

  It seems that GJK fails when the triangles are close to each other but not
  colliding,
  Add a test in test_fcl_gjk with specific triangles and transforms that make
  GJK fail.

Revert "[OBB] Simplify expression in obbDisjointAndLowerBoundDistance", fix #46

This reverts commit 31e52cc9.

[CI] use generated configuration directly

replaced ? by if in sphere_sphere distance for compilation purposes

  If GJK::evaluate fails to converge but that the distance of the origin to the
  simplex converges to 0, set distance and return fail. In shapeDistance,
  return collision if GJK::evaluate failed.

  This test makes GJK fail, reaching the maximal number of iterations.

  - if dir [2] == 0, return a point with z coordinate equal to 0,
  - add a test between box and cylinder that did make GJK algorithm fail.

  Methods BVTesting with sqrDistLowerBound as output argument were not defined.
  Instead the implementation of the base class BVHCollisionTraversalNode <BV>
  was called instead. Unfortunately, in the base class, the meshes and
  bounding volume hierarchy were moved to the position given for collision
  testing, but not in the derived classes. Method overlap were then called with
  wrong argument for position and orientation.

  distance lower bound is necessary to compute security margin. In the previous
  state of the code, security margin was not computed if distance lower bound
  was not selected.

  - This member is used to convert a octomap to a set of boxes.

  This test was malformed. It tested collision for tangent shapes and checked
  that A against B and B against A were collision free.

  - many tests put shapes in singular configuration so that normal and depth
    are ill-defined. This modifications removes tests that are not relevant.