ADD: component export MDD format (for animation)

git-svn-id: svn://scm.gforge.inria.fr/svnroot/sofa/trunk@9872 b7f1a160-662a-0410-a6d8-bea165342f16
ADD: component exporter for STEP format

git-svn-id: svn://scm.gforge.inria.fr/svnroot/sofa/trunk@9873 b7f1a160-662a-0410-a6d8-bea165342f16
Compliant: modifications relative to changes in CompliantDev

git-svn-id: svn://scm.gforge.inria.fr/svnroot/sofa/trunk@9874 b7f1a160-662a-0410-a6d8-bea165342f16
Collision detection: fixed wrong contact point computations

git-svn-id: svn://scm.gforge.inria.fr/svnroot/sofa/trunk@9875 b7f1a160-662a-0410-a6d8-bea165342f16
RigidSphereModel: do not recompute surface contact point if already computed during intersection test (Particle SphereModel always returns its center as contact point).

git-svn-id: svn://scm.gforge.inria.fr/svnroot/sofa/trunk@9876 b7f1a160-662a-0410-a6d8-bea165342f16